The genus Athroisma (Asteraceae, Heliantheae)

of the Linnean

BotanicalJournal

Society (1995),

7 19: 101-184.

With

41 figures

The genus Athroisma (Asteraceae,

Heliantheae)

TORSTEN EFWCSSON Botaniska

institutionen,

Received December

Stockholms universitet, S- 106 9 7 Stockholm, Sweden

7993, acceptedfor

publication

June 1995

The palaeotropical genus Athroirma (Asteraceae, Heliantheae) is revised for the first time, and its general morphology is described. Twelve species and two subspecies distributed in East Tropical Africa, Madagascar, and in Asia from north-eastern India to the Sunda Islands are recognized. Four new species are described (A. inevitabile and A. pusillum from East Africa, and A. pinnalijdum and A. psilocarpum from Madagascar). One species is reduced to subspecies rank (A. gracile ssp. psyllioides). Some species have conflicting character patterns which intergrade. Thus, the delimitation of species is discussed, and a hypothesis of introgressive hybridization in th e genus is formulated. Distribution patterns in East AMca are examined in relation to introgression in three species complexes, connected to A. gracile. In two of the cases, the character distribution is explained by a single dispersal event and subsequent introgressive hybridization. A hypothesis of the phylogenetic relationships within the genus is presented, based on a cladistic analysis of 36 morphological characters. The stability of the single most parsimonious cladogram is tested (decay, skewness and random character weighting), and found to be low except for three nodes. An analysis with putative hybrid groups included is also presented. A key to all taxa is supplied as well as nomenclatural consideration, descriptions, drawings and distribution maps. Chromosome counts of three species are reported (2n=20). 0

KN.5 The

ADDITIONAL introgression

Linnean

Society

or London

KEY WORDS:-chromosome - node support - phylogenetic

counts - cladistics systematics - taxonomy.

-

hybridization

-

CONTENTS Introduction . . . Background . . . . Generic delimitation and systematic position Problematical groups : Material and methods Statistics . . . . Phylogenetic analyses . Taxonomic concepts . Results . Morphology and characters Phylogenetic systematics Species delimitation . Taxonomy . . . Key to the species . . . Acknowledgements . . . References . . Appendix . . . 0024-4074/95/010101+84$12.00/0

102 102 102 104 104 106 106 108 108 108 122 126 137 138 181 181 183

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101 0 1995 The Linnean

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102

T. ERIKSSON INTRODUCTION

. Background The genus Athrotia was described by De Candolle (1833), who based the genus on a plant from Burma known as a Sfhaeranthus L. (Wallich, 18281849). Later, Oliver (1894) described the new genus PoZycZine, based in part on a plant from East Africa which he himself earlier had described as a A number of species Sphaeranthus (Oliver, 1885), and one other collection. were then subsequently described as belonging to PoZycZine (Hoffman, 1894; Klatt, 1895; Humbert, 1923; Dandy, 1926; Chiovenda, 1931). In France, Gagnepain (1920) described a new genus Etheocephalus based on a plant from Cambodia, which was later discovered to be conspecific with Athrotima Zaciniatum (Merxmiiller, Leins & Roessler, 1977). Mattfeld (1936), in describing A. hastifolium from East Africa, noted that it was similar to the homogamous species of Polycline, except for its heterogamous capitula, a character of the Asian genus Athrokma. He concluded that there was no reason to distinguish between the two genera and moved all known species of PoZycZine to Athroisma. Even though the merging of Athroisma and Polycline seems not to have been universally accepted (Humbert, 1962), Athroisma was treated, at the Reading Symposium on Compositae in 1975, as comprising both the genera PoZycZine and Etheocephalus (Merxmuller et al, 1977). I reached the same conclusion (Eriksson, 1990) based on a cladistic analysis which indicated a monophyletic origin for the genus Athoisma including the species formerly in PoZycZine. De Candolle (1833, 1836) considered Athrotima to be a close relative of the genus S’haeranthus in the tribe Inuleae, and this view has persisted since then (Bentham, 1873; Hoffmann, 1889-1894; Mattfeld, 1936; Merxmtiller et al, 1977) until recently (Eriksson, 1991) when I argued for the transfer of this genus, along with Blepharispermum DC. and Leucoblepharti Arnott, to the tribe Heliantheae. It is noteworthy in this context that Oliver (1894) when describing PO&line observed that several characters “remove it far from S’haeranthus”; and that Gagnepain (1920) found similarities between his newly described Htheocephalus and the Heliantheae. Athrotima has been partially treated in regional floras (Agnew, 1974; Backer & Bakhuizen van den Brink, 1965; Chiovenda, 1932; Clarke, 1876; Hooker, 1881; Humbert, 1962; Koorders, 1912) but no complete treatment has attempted since that of Mattfeld (1936). Some Athroivna species have been poorly understood, especially those with seemingly intergrading character patterns (Eriksson, 1990) in East Africa. This work, which is a continuation of my investigation of a small group of genera (the Blepharispermum group comprising the genera Athroisma, Leucoblepharti, and Blepharispermum; Eriksson, 1990, 1991, 1992) presents a revision of the genus Athroisma. Generic delimitation

and systematic position

A phylogenetic analysis of generic interrelationships was presented at an earlier stage of my work on the Blepharispermum group (Eriksson, 1990). The main thrust of that analysis was an investigation of the generic boundaries

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within the group of genera, especially in relation to LeucobZepharz3 subsessilis (DC.) Amott. The analysis indicated that the genus Athroisma was monophyletic and well delimited with eight synapomorphies, five of which were without homoplasy. A few of those have been reinterpreted, but the following synapomorphies are accepted for Athroisma. Plants herbaceous, often woody basally. Pappus present as a corona of at least basally Twin-hair apices divergent to revolute. Endosperm lateral cell walls sinuous.

connected

twin-hairs.

The systematic position of Athroisma is dealt with in Eriksson (1991) and the main reasons for a position in the Heliantheae rather than in the Inuleae will only be summarized here. A position in the Inuleae is not supported by the shared characters since they were revealed to be symplesiomorphies (presence of anther tails; lack of second columellae layer in the pollen; caveate pollen type), or probable parallelisms (female tubular florets; glomerules). Synapomorphies linking the genera with the Heliantheae, on the other hand, were accepted; most important being carbonized cypsela walls and anther appendage ovate with constricted base. These have been found to be characteristic of a group of genera comprising the Heliantheae (Robinson, 1981; Bremer, 1987) but excluding the Inuleae. In a study of the subfamily Asteroideae (Karis, 1993b) a clade comprising the Eupatorieae and the Heliantheae s.Z. is supported by trinerved leaves, isodiametric anther endothecial cells, and carbonized cypselas. Those synapomorphies are shared by Athroisma. Athrotima and Blepharispermum were analysed chemically by Zdero, Bohlmann & Mungai (1991). They attempted to interpret the systematic position of these genera in the Inuleae (in a wide sense), on the grounds that the compounds found in Athroisma and Blepharispermum (thymol and ent-labdane) are common there. They pointed out, however, that those compounds are also found in genera within the Heliantheae (although not so commonly). Their results indicate that the presence of those compounds may be uninformative when choosing between the Inuleae or the Heliantheae as relatives of Athroisma. In a recent paper, Karis (1993a) analysed a large number of Heliantheae genera (including Helenieae) and some Eupatorieae, and for the first time Athroisma was included. In his cladogram Athrotima is found in an unresolved tetratomy at the base of the Heliantheae (in a wide sense) close to a paraphyletic Helenieae. Some of the genera placed rather close to Athroisma in his cladogram have anther tails very similar to those of Athroisma, BZepharispermum and Leucoblepharis. The Ecliptinae as delimited by Robinson (1981), where I provisionally put Athrotima (Eriksson, 1991), was shown by Karis to be paraphyletic, and some Ecliptinae genera are, in his cladogram, found just above the Helenieae grade. Hence, Athroisma belongs to the Heliantheae, possibly close to the ‘base’. The lack of certain characters of the capitula (e.g. those pertaining to ray-florets) make the exact position hard to elucidate. According to the unpublished molecular data of Kim (pers. comm., cf. Kim & Jansen (1993)) the g enera Athroirma and Blepharispermum

T. ERIJSSSON

104

always form a monophyletic group with a suggested not within Yhe core part of the Heliantheae”. Problematical

position

close to but

groups

One species, Athroisma grade, is involved in all cases where intergradation is a problem for species delimitation. In the northern and north-eastern part of its distribution area, specimens are found which are intermediate to A. boranenq in the south-east, intermediates with A. ha-+&urn are found; and in the north-west, specimens occur which seem intermediate between A. grade and A. stuhlmannii, Seven species have been described which are involved in these species complexes. The intermediate groups show more or less intergrading character patterns and a lack of autapomorphies. Groups of specimens which are intermediate between two species may be interpreted simply as belonging to an intermediate species or as being of hybrid origin. If their synapomorphies are congruent with those of other they are best interpreted as species, i.e. more inclusive sets of homologies, non-hybrid intermediate taxa. If the apomorphies are in conflict, however, hypotheses of hybrid origin may be appropriate. Phylogenetic analyses may if the species between which the group is give additional information: intermediate can be shown to be relatively distantly related, this would support a hybridization hypothesis. More or less continuous geographical variation between two species may be due to change over an environmental cline (Grant, 1981), or to the presence of introgressive hybridization. Introgressive hybridization is known (Anderson, 1949; Grant, 1981; State, 1989) in many groups and relies upon at least partial fertility of hybrids. The recognition of hybrids is problematic. Methods have been suggested, none of which is sufficient as proof of hybridization: overall intermediacy of specimens, shared ‘autapomorphies’ of parent species, experimental synthesization of hybrids, ‘hemi-apomorphies’ etc. (cf. e.g. State, 1989; Wagner, 1983; Wanntorp, 1983 and McDade, 1990; 1992). According to Smith (1992), the best indication of introgression is a mosaic geographical character distribution pattern. Molecular approaches have been developed (Rieseberg & Brunsfield, 1992) which may yield less ambiguous data. In the present study, I have worked mostly with herbarium material and investigated the geographical distributions of characters in order to formulate hypotheses of species boundaries and the interaction between species. MATERIAL

AND

METHODS

This revision is based on morphological information assembled from the study of herbarium material. In addition, three species were observed and collected in the field in Tanzania and Kenya in June-July 1990. Seeds of these collections have been cultivated in the greenhouses at the Department . . of goyy, Stockholm Umversrty. er armm material from A, ALF, B, BM, BR, C, CAL, DSM, E, EA, ETH, FT, G (incl. G-DC), GH, K, L, LISC, M, NHT, P, S, SRGH, UPS, W, and 2 was used for this study (abbreviations according to Holmgren,

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Holmgren & Barnett (1990)). The following herbaria were visited during the course of the study: A, BM, DSM, EA, G (incl. G-DC), GH, IS (incl. K-W), NHT, P, S and UPS and all cited collections (395 collections, 669 sheets) were examined except where noted. Lost collections are indicated with ‘t’. Leaves and floral parts were softened by boiling in water (with an added detergent), and examined in a preparation microscope. Drawings of floral parts were made by way of the camera lucida method. Habit drawings were made from mounted herbarium specimens. Some parts (corollas, anthers, styles, cypsela and leaf surfaces) were mounted in Hoyer’s solution (Anderson, 1954) and examined under the microscope. Note that the drawings of the cypselas are simplified and not black even though all species have black cypselas. All drawings were made by the author, except Figure 2 which was drawn by MS Pollyanna Lidmark. Abbreviations of authors follow suggestions in Brummitt & Powell (1992). Terms are used in the sense of Stearn (1973). Statements of colour are either the author’s observations, information from collection labels or, in the case of well-preserved specimens, observations on collected material. Measurements in brackets refer to situations where single specimens vary significantly from the other specimens. For example (A-)B-C means that there is a more or less continuous variation between B and C, and that one (or a few) of the measured entities have A and that there is a gap between A and B. In order not to burden descriptions inordinately, autapomorphic features are generally not included but put before the description, in a special paragraph. Fully grown parts have been measured where possible. Measurements of parts of the capitula have been rounded to nearest 0.5 mm, except for the measurements on the stamens, the twin-hairs, and the cypsela neck which have been rounded to nearest 0.1 mm. The various scales of the capitula were measured in flattened condition. The style measurements do not include the stylophore. In the list of collections, the localities found on the sheets have been translated into English. The names of places and administrative areas within the countries were adjusted to follow the Times Atlas ofthe World (Bartholomew, 1990) a< far as possible. In cases where names were not found on those maps, they were adjusted to the maps of Africa published by the Defence Mapping Agency, Washington DC, U.S.A., or to local maps. When the adjustment of the names to current spelling was uncertain, the spellings found on the collections were included within brackets. In certain cases, indices of collecting localities (Bamps, 1968; Polhill, 1988) were used to locate collecting sites. A few old (type) localities were identified by use of travel accounts etc.: Keller (1896), Engler (1904) and Chiovenda (1916). The information on distribution and habitat and some additional notes on vernacular names were compiled from the herbarium sheets and, where explicitly stated, from other sources. Altitude information in feet was converted to metres (25 m intervals). Specimens on which the chromosome counts were based are referred to by their acquisition numbers (at the Department of Botany, Stockholm

106

T.EFUKSSON

University) and by their corresponding field numbers. Sections of root-tips were treated with a 0.2% solution of colchicine, stained in aceto-orcein, fixed in Camoy’s solution and mounted in euparal. Cypselas used for the SEM pictures were picked untreated from herbarium sheets, coated with gold and photographed in a Cambridge scanning electron microscope. Statistics Of each collection, five instances of the characters used were measured, where possible. The mean of these measurements were chosen for usage in the subsequent treatment. Standard deviations were not computed. The petiole); leaf width; following characters were used: leaf length (including number of leaf margin teeth along one side of a leaf; plant height; distance between uppermost leaf and base of glomerule; cypsela surface protuberances (four classes: smooth; tuberculate; ridged; rugose), cf. morphology and characters section. Phylogenetic analyses Autapomorphies as well as character-states shared by all taxa in Athroisma were omitted from the cladistic analysis since they lack potential information in relation to phylogenetic relationships. The ingroup consisted of all species recognized by the author in Athroisma, and the genus Leucoblepharis together with one species of Blepharispermum were used as outgroups. See phylogenetic systematics section for a discussion on choice of outgroups. The data set (Table 1) was analysed on a Macintosh computer using PAUP (Swofford, 1993). All ch aracters were treated as unordered. Missing data were scored with a hyphen (-). Polymorphic taxa were scored with all observed states. The data set was searched for shortest cladograms using the Branch-andBound option. The Acctran option was used for the character optimizations. Consensus trees were computed using the strict option. MacClade (Maddison & Maddison, 1992) was used to edit the data matrix and to compare character distributions on the cladograms obtained by PAUP. Output from MacClade was also used as a basis for the cladograms in Figures 9-12. The stability was tested with following methods: (1) For the analysis of the character support of the nodes in the cladogram six additional analyses were performed in which the length of the accepted cladograms were increased one step at a time until no resolution at all remained in the strict consensus (Bremer, 1988), Decay analysis (Donoghue et ak, 1992). (2) The random character weighting analysis (Trueman, 1993) was performed by assigning a base weight (100) to each character and then allowing the weight to vary randomly around this base weight within a given range (percentage). For example: 20% deviation would give weights in the interval 80-120. For percentages above 100 the randomized weights

THE

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107

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were constrained to be non-negative. One thousand randomized weight sets and corresponding PAUP runs were performed for each percentage (1, 5, 10, 25, 50, 75, 100, 150) with the settings hsearch, mulpars, TBR branch swapping, and Acctran. The trees obtained in all analyses for each percentage were assembled into a single tree file, loaded into PAUP, and a strict consensus was made. For each node in the original cladogram, the percentage at which the node was lost in the consensus was noted. (A HyperCard Stack ‘CWR-Character Weight Randomize? was developed for the non PAUP part of the analysis. This stack may be obtained free from the author). (3) The exhaustive searches for the skewness analysis (Hillis & Huelsenbeck, 1992) were made with the PAUP exhaustive search command, evaluating only those trees which satisfied constraint trees made in MacClade’s tree window ‘by hand’, saved to disk, and subsequently loaded into PAUP using the load constraints command. The permutations of the data were made using the ‘shuffle’ command in MacClade.

Taxonomic

concepts

When treating the genus Athroisma, I used a species concept based on morphology. Species are recognized on disjunctions in morphological characters (Du Rietz, 1930; Stebbins, 1950). For the purpose of this treatment I regard the morphological entities, the species, to be exclusive groups (de (basal) cluster(s) of Queiroz & Donoghue, 1990), recognized as “irreducible organisms, diagnosably distinct from other such clusters, and within which there is a parental pattern of ancestry and descent” (Cracraft, 1989). The species in Athroisma have uniquely derived characters (autapomorphies), or unique combinations of characters, which make it plausible to treat them as species. Subspecies are here used in the sense of Du Rietz (1930): regional distinct parts of a species which intergrade in a meeting zone. This is only used in A. grucile. The variety rank has previously been used within the genus, but the specific case (A. borunenre) is not regarded as meriting taxonomic recognition.

RESULTS

A4orpholoa

and characters

Below is a discussion of general and detailed morphology, as well as the results of the character analysis (with the character numbers, cf. Table 1). It is important to note that the definition of characters were made in a phylogenetic context, which means that the character states represent hypotheses of homology. Certain characters are treated differently here than in the previous analysis (Eriksson, 1990). In referring to the character numbers of the previous paper the prefix ‘L’ has been used. Hence, Ll indicates character number 1 in that analysis. All characters which were informative for Athroisma in that analysis, except one (L2, see below under character l),

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were used here also. In addition, three characters used here were uninformative in the previous analysis. characters sufficient gaps were present in the In the ten quantitative measurements to merit their use as discrete character states. Uncertainties are all coded as ‘missing’, but are of two classes: (1) Data missing or uncertain. This occurred when it was impossible to assign a state because of, for example, a lack of material of that part of the plant. (2) Data not applicable. This occurred when a character was found on a part of the plant which was absent in some taxa. An example of this is character 11 (hair type) in which the glabrous taxa have been coded ‘missing’. I have tried to use such coding as little as possible since it may result in meaningless states being assigned to the taxa in question during the analysis.

Habit Most species are medium sized (approx. 50 cm high) rhizomatous herbaceous plants of more or less open grasslands. Some are shrubby and some annual. The latter being difficult to distinguish on herbarium material, decisions are based on the presence of rather weak roots without any tendencies towards rhizomes or thick roots, as well as a lack of woody bases. The annual species grow mostly in temporary wet areas or in swampy ground. In the cases where specimens were observed during a longer time in the greenhouse, Athroisma stuhlmannii was an ‘obligate’ annual since it died after flowering for some months, contrary to the other observed species from the same general area (A. gracile and A. hastz@um), grown under the same conditions. Habit

characters:

(1) Lifeform

(Ll). Th is character has been used in slightly different form in previous analyses (Eriksson, 1990, 1992). In this case, only one of the apomorphic states (2) in character Ll was applicable, and that has been divided into the ones used here. Without observing the plants during an acceptable time it is hard to determine if they are annual or not. In one case, A. psilocarpum, where only one young collection existed, I have not assigned any character state but used ‘missing’. States: 0 - subshrub or shrub; 1 - herbaceous annual. The presence of persisting petiole bases which was used in my previous analysis (character L2) has not been used here. The reason for this is that although this is informative within the genus Blephartipermum it seems here to be directly dependent on character 1. Stems and shoots Underground parts are lacking in many collections. The genus Leucoblephare is reported to have woody ‘root-stocks’ (Amott, 1838). None of the specimens examined (Eriksson, 1990) of that genus included any underground parts, and the root-stock is treated here as a short rhizome (Lawrence, 1989). In most species, the primary shoot terminates in a glomerule and one, or usually two, secondary shoots emerge from leaf axils below the primary glomerule (e.g. Fig. 25). Thereby the branching of the whole plant is

110

T. ERIKSSON

determined by the dichasial branching of the ‘synflorescences’ of glomerules. and Leucoblepharti This general pattern is found also in Blepharispermum (Eriksson, 1990, 1992). When plants grow old and sometimes shrub-like, the branching pattern is obscured by a general thickening of the main branches, and by subsequent new shoots appearing more or less unrelated to glomerules from old leaf axils. See below under Synilorescences. Shoots are in som& species pubescent when young, becoming glabrous when old and woody, like in Blepharispermum (Eriksson, 1992), and the same kinds of indumentum are found on the leaves. In about half of the species in Athrotima, however, even young shoots are consistently glabrous. In the centre of the stem is a loose tissue which in many cases has ‘deteriorated’ so that the stems are hollow. Stem characters: (2) Rhizome. The presence or absence of a rhizome is ambiguous in the outgroup: I have not seen any in [email protected] (E&son, 1992) but there are indications of one in Leucoblepharis (Eriksson, 1990) to which I have parts where assigned state ‘present’. The species in which no underground seen have been coded ‘missing’. States: 0 - rhizome present; 1 - absent. (3) Pubescence of young stems. In this character only the youngest stems are applicable since old stems may have lost their hairs. In one species, A. pinnatzjidum, hairs were found only at the apices of the very youngest branches, and it is coded as having hairs. States: 0 - hairs present; 1 absent. Leaves The leaves show considerable variation among the species and they have some good diagnostic characters. They are alternate and entire or dissected. Some have distinct petioles and in others they attenuate towards the base. In the species with more or less linear leaves it is not possible to pin-point the petiole, even its presence. In some other cases (due to the attenuate bases of the leaves) petiole length is approximate since it is not possible to indicate a junction with the lamina. In the two species which have deeply dissected leaves the distance up to the base of the most basal lobes is considered the petiole. Five species have more or less incised or lobed leaves (A. Zobatum, A. laciniatum, A. proteifrme, A. pinnatiJidum and A. psilocarpum). In some A. Zobatum and A. psilocarpum they are only dentate or very shallowly incised, while they are always more deeply lobed in the other species. The lobes are never dentate in A. proteiforme and A. pinnatz$dum but in the former they may be very short so that leaves look dentate. The petiole bases are simple, and there is no trace of gibbosities etc. as in Blepharispermum (E&son, 1992). The leaf apex and the apices of the teeth are thickened, and slightly apiculate in some species (A. Zobatum). The surfaces of the leaves are either glabrous, or furnished with gland dots, uniseriate hairs, or biseriate glandular hairs. Hairs and glands are most abundant on the lower surface except in A. proteiforme and A. pinnatzfzdum where glands and hairs are found only on the upper surface. In general,

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Figure 1. Trichomes on leaves. Uniseriate hairs: A, Adroisma boranense (Sebsebe 1228); B & C, A. hastifolium (Greenway 9798); D, A. pinna~ifidurn (Afielius s.n.). Biseriate glandular hairs: E, A. boranense (Sebsebe 7228); F, A. hastifolium (Greenway 9198). Gland dots: G, A. boranense (Sebsebe 1228); H, A. has@lium (Greenway 9198). Scale bar = 0.1 mm.

hairs of both types are found more frequently on veins and are larger than on the lamina proper. Gland dots are found mainly on the lamina and more rarely on veins. Gland dots as well as both types of hairs may also be present on stems, and gland dots also within the glomerules. The uniseriate hairs (Fig. lA-D) are similar to those of the genus BZepharispermum. They vary among the species from almost moniliform (Fig. lD, e.g. A. pinnatz@um) to thick and ‘robust’, and are usually curved, possibly as a result of pressing. The gland dots are yellow or reddish in dry material and seem to be colourless in living leaves, the latter seen only in A. hastzjdium. Like the glands on the corolla they are trichomes with cells in two rows of which the lower ones (the stalk) are very short and the two uppermost (the gland) swollen (Fig. lG, H). In poorly preserved material, the gland dots may be hard to observe. Biseriate glandular hairs are found in a few species, abundantly in A. boranense and more rarely in A. hastifolium and A. pusillum They are short, straight hairs with cells in double rows and with a small apical gland (Fig. lE, F). This gland is brownish in dry material but colourless in living leaves, at least in A. ha.rtifoZium (cf. gland dots). The glandular hairs are also present in certain collections intermediate between A. grade and A. boranense or A. hartifolium. In two species (A. hastifolium and A. boranense) dry leaves remain at the bases of the stems. This is hard to see in vigorously growing young specimens but is otherwise easily observed. Leaf characters: (4) Dry basal leaves. This character can be observed only in old specimens. States: 0 - leaves not remaining; 1 - remaining. (5) Leaf length by width ratio. This character is only applicable to the largest leaves of the specimens. In A. boranense some collections have small leaves which fall in the lowermost part of state 1, being 3-4 times as long as wide,

112

T. ERIKSSON

and it is therefore coded as being polymorphic in this character. In A. stuhlmannii, however, only one specimen is outside the normal range for the this. A. proteiforme is a special case since it species, and I have disregarded is variable in regard to the presence of leaf lobes. When lobes are absent the leaves are narrow and may be almost linear, and therefore get a high length by width quota. It is coded polymorphic in this character. States: 0 less than 3.5 times l&ger than wide; 1 - more than 3.8 times longer than wide. (6) Incision. This character was used previously (LlO) but the states were assigned slightly differently. Here I have coded A. lobatum and A. proteifrme ,polymorphic. A. psilocurpum is coded ‘missing’. States: 0 - leaves entire; 1 incised or lobed. (7) Leaf margin. This character was also used previously (L8). At the time, however, I had not realized that A. protezjxme (sensu Humbert) comprised three taxa, and this character was interpreted erroneously. Two of the species (A. proteiforme and A. pinnatifidum) actually were apomorphic in this character. Note that in wide leaves of A. stuhlmannii, A. inevitabile and A. proteaforme the leaf margin may be almost flat in the apical part of the leaf while involute basally. These have been coded as involute. States: 0 - leaf margin flat or revolute; 1 - involute. (8) Leaf buses. In some species the bases of the leaves are in the form of petioles, in others the lamina are smoothly attenuate. Previously I used the character ‘petiole distinct’ or ‘indistinct’ (Lll) but since it is hard to determine if linear or almost linear leaves have any petiole at all, the definition of the character has been reinterpreted. A. proteiforme is variable in this character due to the presence or absence of lobes on the leaves. States: 0 - lamina shortly attenuate to cordate; 1 - very attenuate. (9) Surface pubescence. This character concerns the position of the uniseriate hairs present on the leaves on many species in Athroisma as well as in Blepharispermum. Taxa lacking such hairs are coded ‘missing’, one of the outgroup taxa (Leucoblepharis) among them. States: 0 - hairs present on both sides or at least on lower side; 1 - present above only. (70) Leaf gland dots. The polarization of the character is reversed as compared with that of the previous analysis of all three genera (character L6). States: 0 - glands present; 1 - absent. (77) Uniseriate hair @e. Like in character 7 the assignment of A. proteifrme has been reconsidered (character L7) since it is treated here as three species. States: 0 - hairs thin, cells small (Fig. 1 D); 1 - + thick, cells large (Fig. lACl. (72) Gland hairs. These biseriate gland hairs are found only in three species, in some of the intermediates between A. gracile and A. borunense and in a single specimen of A. gracile spp. psyllioides. States: 0 - gland hairs absent; 1 - present. (73) Petiole hairs. In some species, the marginal hairs on the petiole and basal part of the lamina are distinctly larger and longer than elsewhere on the leaves. A. Zobatum is variable, some having long hairs and others having shorter ones. Hence it is coded polymorphic. The species which lack uniseriate hairs are coded as ‘missing’. States: 0 - petiole hairs short; 1 - at . least l-l.5 mm long.

THE

GENUS

ATHROISMA

113

Sy njlorescences The word ‘synflorescence’ is here used for the arrangement of glomerules even though the glomerules themselves constitute synflorescences in the usual sense. Basically it is dichasial (cf. shoots and stems above) but there are some variations on that theme. The pedunculoid branch (cf. Eriksson (1992)) terminates in a glomerule with subsequent shoots emerging from below. In some species such lateral shoots are uncommon at least in the first year, thereby making the synflorescence ‘simple’ (Fig. 29). In most species there are secondary shoots which may be few to many, forming a synflorescence. In a few species, the secondary branch or branches dominate, giving the stem an appearance of more or less continuous growth with lateral glomerules. In two species (A. stuhlmannii and A. inevitabile), this results in almost evenly spaced glomerules along the stem (Fig. 40). Since these species have very short or absent pedunculoid branches it is a distinct characteristic. In most cases A. stuhlmannii has two branches below each glomerule in the lower portion of the plant, in a strikingly regular manner. A. pusillum has apparently lateral glomerules (Fig. 33) rather regularly spaced alongside the stem, but when studied in closer detail a monochasial branching is revealed. Synflorescence character: (74) SynjZorescence. In a few species there is usually only one apical glomerule but since those are sometimes dichasial I have disregarded this distinction. Other species have more or less consistently only one branch continuing from below each glomerule. A. Zaciniatum is variable in this regard and is coded polymorphic. States: 0 - dichasial; 1 - monochasial (at least apically). GZomeruZes The capitula are arranged in a very shallow spiral on the glomerule, but this is hard to observe. Instead, a secondary spiral pattern (parastichy) is visible (Fig. 2). That this is not the real spiral is revealed by the upper end of the spiral being slightly to the side rather than at the apex of the glomerule. The capitula are situated on a narrowly conical ‘spiciform’ receptacle. This often remains in old glomerules when capitula have fallen off, making the remains look like a small pincushion. In the -descriptions the phrase ‘leaves reaching x mm below the glomerule’ indicates the distance from the base of the glomerule to the insertion point of the uppermost leaf. Glomerule characters: (75) Pedunculoid branch. In A. boranenre and A. hastifolium the glomerule is usually alone in the apex of the shoot and the leaves end well below it. This character is somewhat variable depending on age of plant and place of collection. States: 0 - pedunculoid branch with short leafless part; 1 - with long leafless part. (76) GZomeruZe form. The ellipsoidal form is seen mostly in old glomerules and is slightly variable in the two species having this character. Here I take the position that they have the character even though they are variable. States: 0 - glomerules spherical or semi-spherical; 1 - often ellipsoidal.

T. ERIKSSON

114

\

I

\ \

/ \

I

Figure 2. Glomerule of Athroisma hastifolium (Greenway 9798) and its parts. Below: an entire glomerule. Note the parastichiai spiral. Ccntre: one capitulum removed from the glometule. To the left of cenke: the subtending bract removed. Top yf: a female floret removed with an involucral bract. Top right. a hermaphrodite floret removed with its palea. Cf. Fig. 29.

THE GENUS AZiYROISUA

11.5

Capitula The interpretation and homology assessment of capitular scales follows previous treatments (Eriksson 1990, 1991, 1992; Fig. 2). The capitula are, at least in well grown glomerules, almost fusiforrn, and circular in cross section. A capitulum is subtended by a bract and consists of two opposite lateral involucral bracts which subtend the filiform female florets, and several hermaphrodite florets all subtended by, and surrounded by paleae. The number of hermaphrodite florets seems not to be fixed, but correlated to the size of the glomemles. The top florets are usually tiny, looking reduced, and these have been counted but disregarded in measurements of floret size. Subtending bracts, involucral bra& and paleae. The subtending bracts are usually shorter than the capitula, except when the capitula are young. They are large and leaf-like in some species, while in others they are smaller and scarious, and may be shiny white or purplish. They are similar to, yet different from normal leaves in that they often show distinct features which appear on normal leaves while also having characters of their own. It is difficult to assess the degree of independence between leaf characters and the characters of subtending bracts, and characters in subtending bracts are generally treated as independent. If the characters actually were dependent upon each other (cf. e.g. characters 7 and 19) this results only in a weighting in favour of the information contained in the characters. In general, subtending bracts of capitula basally in the glomerule are larger than apical ones. Also, the apical subtending bracts are often widest towards the apex while the basal ones are wider towards the base. Apically the subtending bracts are acute or acuminate with an involute margin in many species. Those species also have more or less involute leaves. The margins of the subtending bracts are in most species fringed or ciliate, and widely or narrowly hyaline. The surfaces are glabrous, or glandular with glands like those of the corolla, and may be pubescent with short uniseriate hairs, and in one species (A. boranense) with biseriate glandular hairs (cf. leaves). This indumentum is present on the abaxial side only, except in A. proteiforme and A. pinnatzjidum which are pubescent only on the adaxial side of the bracts, as well as the leaves. Here ‘bracts’ are used as an abbreviation for ‘bracts subtending the capitula’. Most species (except A. boranense, A. hastifolium, and A. Zaciniatum) lack female florets and mostly also involucral bracts. In A. Zobatum, however, involucral bracts are present which do not subtend any florets. In other species the basal paleae are somewhat like involucral bra& (opposite, thicker than paleae, and sometimes slightly pubescent abaxially) but they subtend hermaphrodite florets. Therefore, and since they are lobed like paleae apically, they are treated as paleae. The involucral bracts are obtuse and slightly boat-shaped, and they surround the female florets closely. They are very similar to the involucral bracts in Blepharispermum and Leucoblepharis, and have a ciliate margin and a glabrous or pubescent abaxial side (uniseriate hairs only).

116

T. ERKSSON

The paleae surround the hermaphrodite florets. They are thin and easily flattened, in contrast to the. subtending and involucral bracts which are thicker. Their outline is usually ovate to obovate (when flattened) or notably almost rectangular in some species. Basally, the sides are more or less adherent, and this is distinct in A. Zuciniutum while less clear in other species. The apex is ciliate and in most species indistinctly three-lobed with a small middle lobe, but almbst truncate and irregularly lobed in others. Characters of bracts and scales: (17) bnation of subtending bracts. In Leucoblepharis the subtending bracts are large and leaf-like (Eriksson, 1990), and this was also seen in a few species 1992). In Athroisma the subtending bracts of in Blepharispermum (Eriksson, one species (A. psilocurpum) are large and leaf-like while two species have slightly leaf-like bracts with visible venation. In all other species there is one visible midvein only. States: 0 - subtending bracts with only midvein visible; 1 - with distinct lateral veins. (18) Subtending bract apices (L74). States: 0 - apiculate to acuminate; 1 - acute to obtuse. (19) Subtending bract margin. This character is in some way correlated to character 7, direction of leaf margin, since the bracts subtending the capitula are of course leaves. I have used it since this character is not totally congruent with character 7. Also, it is somewhat different from character 7 in that here it is the apex that is most markedly involute while on the normal leaves it is the base. States: 0 - margin apically flat; 1 - apically involute. (20) Margin of basal subtending bra&. In almost all species, the subtending bracts of the median and central capitula in the glomerules have ciliate margins. The basal ones, however, are more variable being almost entire or dentate. A. proteiforme is variable in this character and is coded polymorphic. States: 0 - margin ciliate; 1 - dentate to entire. (27) Ada&al side of subtending bracts. This character is correlated to character 9 and might be thought only to weight that character (i.e. the characters are not independent). Since character 9 contains so many ‘missing’ assignments I have chosen to use this character also. States: 0 - glabrous; 1 - pubescent. (22) Colour of basal subtending bracts. Some species are shiny white in the apical portion with a distinctly green nerve (or green central portion of the bract). A few species, however, are slightly harder to evaluate and this depends much on the quality of the collected material. In A. Zobatum both states seem to occur but some of the material is in poor condition. I have coded it polymorphic in this character. States: 0 - dull white or green, nerve indistinct; 1 - white with distinct green nerve. (23) Involucral bra&s. Such are present in the three species which have female florets and in A. lob&urn which have ‘empty’ involucral bracts. States: 0 involucral bracts present; 1 - absent. (25) Paleae apices. The paleae in Leucoblepharis and Blepharispermum are mostly three-lobed apically, and this is also the case in Athrotima where the middle lobe is often distinctly shorter and more narrow than the lateral ones. In certain species the paleae are almost truncate with no or irregular apical lobes. States: 0 - paleae three-lobed; 1 - unlobed or irregularly lobed.

THE

Figure 7228).

3. Cypsela form. A, female Scale bar = 1 mm.

GENUS

floret.

ATHROISMA

B, hermaphrodite

117

floret.

A~hroisma boranense (Sebsebe

(26) Outermost paleae. The outermost paleae have, in the species without involucral bracts, some features usually associated with involucral bracts rather than paleae. The outer paleae always subtend hermaphrodite florets, however, and are similar to paleae as in the case of being apically lobed. For the purpose of this analysis I have considered them to be paleae. States: 0 - outermost paleae without hairs; 1 - with abaxial hairs. Florets The corollas are white, sometimes slightly pinkish, with a green tube. In some species, the bases of the corollas have cells with thickened walls. This is in most cases combined with the corolla bases being somewhat swollen. Female j-orets The female florets are strictly female, lacking all trace of stamens. They are tubular and the corollas are more or less widened at apex, especially so in A. Zaciniatum. The styles lack sweeping hairs and also lack stylophores. The cypselas of the female florets look much like those of the hermaphrodite florets and are not described separately in this paper. They only differ slightly in form, by being less narrow towards the base than cypselas of the hermaphrodite florets (Fig. 3). Character of female florets: (24) Number of female jlorets. Except in the case of A. Zobatum, as mentioned in character 23, the species having involucral bracts also have female florets. This character was used in a previous analysis (character L15) but, as indicated by the character distribution in that cladogram, the presence of

T. ERIKSSON

118 n

Figure 4. Corolla glands. A & B, stalk with basal cells longer than wide (A, Afhroisma boraneme, Sebsebe 7226 J& A. pusilium, Drummond 6’ Hem&y 4073). C, stalk with short and wide cells (A. pinnatijdum, Humbcrt B Swingle 5177). Scale bar = 0.1 mm.

female florets should be treated as a plesiomorphy at the level of Athroisma. The polarization is reversed here. States: 0 - two female florets; 1 - none. Hemaphrodite jl0ret.s The hermaphrodite florets are fully’ fertile and have regular corollas which are five-lobed except for A. Zaciniatum which has florets with four-lobed corollas as well as four stamens. The corolla lobes and the tube in most species are glandular. The glands are biseriate and consist of a short stalk and swollen apical cells. The glands on the corolla tube vary among the species. They may look like those on the corolla lobes, i.e. with a very short stalk of short and wide cells which are not thickened. Some species have glands with elongate stalks: the basal cells are longer than wide and have thickened walls (Fig. 4A, B). Such glands are sometimes hair-like. Two species have short stalks on the glands in which the cells are ‘swollen’ (Fig. 4C, A. proteiforme and A. pinnat$dum). The anthers are colourless or white and sometimes slightly purple. The endothecial cells are about as wide as long, or wider than long with more or less polarized thickenings (Dormer, 1962). One species has radial thickenings (A. boranense). The anthers have short tails, as in Blepharispermum and Leucoblepharis. The styles have a stigmatic area which is (sometimes indistinctly) divided in two rows, and confluent at the apex of the style branches. The sweeping hairs are found mostly at or near the apex of the style branches: they are obtuse and somewhat clavate. Character of hermaphrodite florets: (27) Corolla bases. The corolla bases are swollen in several species but it is quite variable within some species. In three species the swollen bases are consistently present and much wider than the apical part of the cypsela. States: 0 - corolla bases as wide as cypsela neck apex; 1 - swollen, wider than neck apex. (28) Corolla tube glands. The presence of corolla glands was used as a character in the previous analysis (character L21). Here it is used in a more restricted sense comparing the presence of glands on the corolla tubes only. States: 0 - glands absent; 1 - present. (29) Stalks of corolla tube glands. These glands do not look like those present on leaves and stems of some species, which are distinctly wider at base while these are equally wide in all of their length. These are distinctly swollen at apex while the leaf “gland hairs have only slightly or not swollen

THE

Figure (Erikxan

5. Cypselas 673) Scale

in lateral view. bar A = 1 mm,

GENUS

119

ATXROISMA

A, Athroisma B = 0.5 mm.

proteifonne

(Rauh

M863/59);

B, A. gracile

apex. A. gracile and A. inevitabile. are polymorphic in this character. States: 0 - stalk cells shorter than wide; 1 - some stalk cells longer than wide. Cypselm The cypselas are more or less dorsiventrally flattened with lateral ridges which may have dense rows of twin hairs, as in BZephartipermum and Leucoblepharis, or indistinct rows of twin hairs. Both sides of the cypselas are usually more or less convex, but in a few species (A. laciniatum, A. Zobatum, A. proteiforme and A. pinnatz$dum) they are more flat than in the other species. Apically there is a neck (Fig, 5) on which the corolla is set. The neck is set close to the adaxial side of the cypsela. Around the corolla there is a pappoid corona, or pappus, in most species. The pappoid corona is scalelike in some species, and it consists of a ring of basally connected twin-hairs (a shallow cup-like structure), sometimes with narrow projections in a few species which are absent in others (Figs 6A-D; 7A). , The pappoid corona was considered to be non-homologous to the pappus scales in Blepharispermum and Leucoblepharis (Eriksson, 1990), and coded as separate characters in that analysis. They might have been coded into the same character, testing if they were homologous or not (i.e. the congruence test of Patterson (1982): homology would have had to be rejected if the character appeared more than once on the cladogram). In that specific case, an initial hypothesis of homology could not have been rejected. Also, if the pappus in Ath roisma is a structure made up of twin-hairs, as it seems, this might also be the case in Blepharispermum and Leucoblepharis. If so, it is not so easily observable there since the apices of the twin-hairs in those genera are always straight. The surfaces of the cypselas are in most species smooth and set with scattered twin hairs. In a few species, the twin-hairs ‘sit’ upon a small

120

T. ERIKSSON

s.n., Figure 6. Pappuslpappoid corona. A, scale-like pappus of Leucoblepharis subsessilti (Dakell K). B, scale-like corona of Athroisma kxiniatum (Gr@h 905). C & D, semi scale-like corona 7752). Scale bar = A. pinnatifdum (C, Humbert &3 Swing& 57 77); A. f ans & wei (D, Fan&awe 0.1 mm.

tubercle. Other species have tubercles without twin hairs and in a few cases (A. hastifolium and A. gracile spp. psyllioides), the surface is shallowly ridged to rugose (Fig. 7B). The ridges in those taxa are especially prominent apically. See species delimitation section for a discussion of the distribution of that character. The surface lacks striations, a character used by Robinson (198 1). The most prominent feature of the cypselas is the black (‘carbonized’) wall layer (Hanausek, 1912; Robinson, 1981). The punctate formation pattern of the black layer in Athroisma (cf. figs 14-18 in Robinson & Ring (1977), figs ll12 in Robinson (1981)) is typical for the genera within the tribes Heliantheae and Eupatorieae. The cypselas have three veins, one along each lateral margin, and one in the testa. The testa which covers the embryo has slightly sinuous lateral cell walls (Fig. 8B) and the endosperm cells have strongly sinuous walls (Fig. 8A). The twin-hairs (Figs 23H, 25H, 27H, 29H, 33-36H, 38H, 40H, 41H) consist of four cells and have diverging to revolute apical cells. The size of the hairs as well as the degree of curving of the apical cells vary among the species. In A. hastifolium an& to a lesser degree in A. gracile ssp. psyllioides,

TME

Figure 7. A, apical portion of cypsela (He& 189). B, cypsela of A. gracile (Semsei 4086). Scale bar = 0.2 mm.

GENUS

ATHROISM4

121

of AUw~bmn latinialum with scale-like pappoid corona ssp. psyllioides with rugose surface, base to the right

the twin- hairs have very short apices which are hardly diverging at all. A. boranense also has very short and weakly diverging apical cells of- the twinhairs. Cypsela

characters:

(30) Cypsela lateral

ridges. Most species have rounded cypselas with more or less scattered twin-hairs (see also character 35). The material present of A. psilocarpum is not mature enough to determine this character with confidence. Its cypselas seem rather flat but since they are quite young I have coded them ‘missing’. States: 0 - cypsela ridges distinct (i.e. flattened); 1 - not distinct (i.e. rounded). when fully developed is striking but (37) Cypsela surface (L28). This character seems polymorphic. Previously (Eriksson, 1990) I assigned a state ‘rugose’ to A. hastifolium and to what is here treated as A. gracile ssp. psyllioides. Later I A. hastifolium which may be noticed that the case is not simple even within

T. ERIKSSON

122

Figure 8. A, endosperm cell outlines (A. fanhwei,

cell outlines Fanhzwe

(Adroisma Inciniatum, Backer 7752). Scale bar = 0.1 mm.

36793).

B, testa (seed

coat)

due to introgressive hybridization. Here I have used the character with only one apomorphic state. States: 0 - cypselas smooth; 1 - tuberculate to rugose. (32) CypseZu glands. The cypsela glands have here been used in two characters (this and number 33). This character concerns only the presence of glands on the cypselas (previously as L29) regardless of their position. A few specimens of A. borunense have one or a few glands while most specimen lack glands. A. borunense is therefore coded polymorphic. States: 0 - glands absent; 1 - present. (3.3) Position of qpselu glands. Certain species have glands placed in a ring apically just below the neck. Here, the species lacking glands (character 32) are coded ‘missing’. States: 0 - glands not in apical ring; 1 - in apical ring. (34) Puppoid corona or puppus. I have previously discussed the homology of the pappoid corona and pappus scales (character L30 and L31 with reversed polarization). Here, the scale-like pappus of Leucoblephurk and Blephurkpermum is treated as homologous to that of Athroismu. The distinction between the states used here is admittedly somewhat arbitrary. The state ‘1’ although not monomorphic, seems to be intermediate between ‘0’ and ‘2’. I have, however, treated this character as unordered. A. Zobutum is assigned state ‘0’ but is in a few cases more semi scale-like. States: 0 - pappus scale-like; 1 - semi scalelike or ring of twin-hairs; 2 - absent. (35) Twin-hair position. This was defined in the same way in the previous analysis (character L32). A. pinnut$dum seems variable since some specimens have scattered hairs, and it is coded polymorphic. The cypselas of A. psilocurpum are totally devoid of hairs and it is coded ‘missing’ in this character. States: 0 - twin-hairs mainly marginally; 1 - scattered. (36) Twin hair apex. This character has been reinterpreted since the previous analysis (character L33) ‘and subsequently recoded. In some species in Athroirmu the twin-hairs are small, they are not or only slightly divergent apically. They look ‘reduced’ but I have coded them as the out-groups in order to test this ‘observation’. States: 0 - twin-hair apices straight or slightly divergent; 1 - distinctly Y-shaped to revolute. Phylogenetic systemutics A hypothesis of the phylogenetic attempted by means of a cladistic

relationships within Athroismu has been analysis. The method of phylogenetic

THE

GENUS

A77ZROISMA

123

1966) is simple and logically consistent with basic systematics (Hennig, evolutionary tenets (descent with modification). It is now a standard method of systematic analysis (Hull, 1989). This analysis was preceded by an analysis of the generic boundaries within the Blepharispermum group (Eriksson, 1990). There, the genus Leucoblepharis together with the genus Blepharispermum was established to be the sistergroup of a monophyletic Athrokma. Therefore, Leucoblepharis and one species of Blepharispermum (B. spinulosum) are used here as outgroup. The ingroup consisted of all species in Athroisma. The selection of taxa is somewhat different from that of the previous analysis. In the main analysis I removed those groups considered to be the result of hybridization. Therefore A. gracile ssp. p.$lioides (previously A. psyllioides) and the intermediates between A. gracile and A. boranense (previously A. sp. 2) are not included here. Instead I added A. inevitabile, A. psilocarpum and A. pinnatajidum which were discovered later. The ingroup consisted of 12 taxa (Table 1). have to be made in In the analysis, assessments of relative apomorphy order to be able to base groupings on synapomorphy only. This has been done using the outgroup method (Watrous & Wheeler, 1981; Farris, 1982; Maddison, Donoghue & Maddison, 1984). The reasoning rests on an argument of parsimony: Given a hypothesis of ingroup monophyly, a character state present both in an outgroup and in the ingroup is plesiomorphic since the corresponding apomorphic state then needs only to have evolved once within the ingroup. In effect, all polarity decisions were made when the outgroup was chosen. One most parsimonious cladogram was obtained in the analysis (length 77 steps, consistency index 0.66, retention index 0.77, Fig. 9). From the character distributions in Figure 9 it is evident that several character conflicts might make the cladogram unstable, and I have attempted to test its stability. A further reason for such a test may be the result of Hillis & Huelsenbeck (1992) that analyses even of fully random data often result in a single most parsimonius cladogram. The easiest, and perhaps crudest, test is to analyse how the resolution of the cladogram decreases (decays) when less parsimonious cladograms are added and analysed in a strict consensus (Bremer, 1988; Donoghue et al, 1992; EGksson, 1992). The decay analysis indicated only three nodes with any stability (Fig. 10, nodes F, I, K in Fig. 9). The base of the cladogram was completely unresolved. The Bootstrap method has been suggested (Felsenstein, 1985), and widely used, as a way to put confidence limits on the nodes of a cladogram. It has been criticized on several grounds (Sanderson, 1989; Faith & Cranston, 1991) and I have here attempted to use a related method (random character weighting) which avoids certain of the criticized features of the bootstrap (Trueman, 1993). This method also indicated the same three nodes as stable and, in addition, a more basal node with some stability (Fig. 11, nodes B, F, 4 K in Fig. 9). A test of the skewness of the tree length distribution curve was applied as suggested by Hillis & Huelsenbeck (1992). This test indicated that the data set still contained significant signal (as opposed to random noise) when the three nodes indicated as stable above were removed from consideration

T. EIUKSSON

124

I

\ I I I I I

4 12 15 27 36

7 19 29 34’

@ Parallelism, appearing twice $ Parallelism, appearing z twice @ Reversal, appearing once

Figure 9. The single Character optimization

most parsimonious cladogram of 77 with accelerated character transformation

steps (CI = 0.66; (Acctran).

RI = 0.77).

(gl = -0.57; 10 effective taxa; PC 0.01). When the node with weaker stability (node B in Fig. 9) was removed from consideration the signal was no longer significant (gl = -0.16; 8.2 effective taxa; P > 0.05). The skewness test was criticized by Ktilersjii’ et al. (1992) since it might give too high

THE

ATh!ROISM4

GENUS

125

. Figure 10. Strict consensus tree of the shortest cladogram plus all trees one -step longer. Decay indices showing node support (Bremer, 1988; Donoghue ef al, 1992) are indicated for the stable nodes.

values for example if the skewness was caused by the frequency of character states. This was not the case here, which was tested by making 10 permutations (cf. Archie (1989)) of the data set, and then computing the skewness of those ‘new’ data sets. None of these were anywhere near significant according to the table supplied by Hillis & Huelsenbeck (1992). To conclude, the three stability tests of the most parsimonious cladogram agree on three nodes which are moderately stable. The random character weighting method and the skewness analysis indicate the presence of one more node with somewhat lower stability. With the background of the proposed introgressive complexes of A. grade x A. hastifolium and A. Facile x A. boranense the low stability is perhaps not very surprising. More taxa than the above mentioned may be affected by the ‘infection’ of characters from other species. Introgressive hybridization has been shown, for example, to be responsible for the transfer of

25

Figure 11. Collapsed tree based on the information from the random character weights analysis. Au nodes except the ones shown were lost already at a deviation of + 1%. The deviation percentages at which the nodes were lost are indicated.

126

T. ERIKSSON

Figure 12. Strict consensus tree of the 17 most parsimonious cladogxuns obtained intermediate groups were included (length 109 steps; CI = 0.73; RI = 0.78).

when

all

mitochondrial genomes over species boundaries well into other species (Ferris et all, 1983). I n such cases one could expect those species to move around in cladograms of (almost) the same length due to conflicting patterns of apomorphy (Wanntorp, 1983). As shown by McDade (1990, 1992) a common result obtained when hybrids were included in cladistic analysis was the insertion of the hybrids as intermediate taxa basally in a clade with one of the parent species above in the same clade (the one with most apomorphies). Usually, the other parent ‘moved’ closer to that clade than in the results obtained from analyses without hybrids. Consider the consensus tree in Figure 12. This is a strict consensus tree from the 17 most parsimonious trees obtained in a run with all taxa plus the hybrid ‘groups’ included. Some of the McDade effect is seen there: the proposed hybrid groups are basal in the clade with A. pracile, except for A. gracile spp. psytlioides which is interpreted as the sister group of A. gracile spp. grucile. Since the tree is collapsed at the base, it is not possible to see if A. borunense and A. hastifolium are put closer to the hybrids than compared with the shortest cladogram (Fig. 9). It is noteworthy that both the consistency index (0.73) and the retention index (0.78) are slightly higher when hybrid groups are included than when they were not included. This effect was also noticed by McDade (1992) and seems contrary to earlier propositions (Humphries, 1983; Wagner, 1983; Funk, 1985). Species delimitation Most species treated here are taxonomically clear-cut with autapomorphies (Table 2) or distinct combinations of characters. section are discussed only those groups of specimens which intermediate between species. Continuous geographical clines between species do not occur in these cases. A. pciZ-e, for example, is found from an altitude of c.

distinct In this seemed any of 2000 m

127

THE GENUS ATHROZSMA TABLE

2. Autapomorphy

Afhroirma

table. The lowermost three rows are groups hybrid origin. Cf. Taxonomy section

(genus)

A. boranense A. fanshawei A. grade ssp. grade A. hastifolium

A. in&tab&

sp. nov.

A. kx-iniatum

A. lobatum

A. pinnah@um

sp. nov.

to be of

Endosperm cell walls sinuous; hvin-hair apices diverging; pappoid corona of basally connected twin-hairs. Endothecial cells with radial thickenings; glandular hairs on bra&s; Short corolla tube; long cypselas. Short rounded cypselas Leaves as wide as long; long marginal cilia on bracts; (cypsela surface rugose). ._ Pedunculoid branches short apically, longer at base. Hermaphrodite florets with four corolla lobes and four stamens; Stems “inflated”; rooting freely when prostrate; growth habit often prostrate; sides of paleae basally adnate. Presence of empty involucral bracts. Narrowly many-lobed leaves; t-shaped to y-shaped hvinhairs.

-

A. proteiforme

A. @ilocarjmm

sp. nov.

A. pusilIum sp. nov. A. stuhlmannii

A. grade

hypothesized

ssp. @yUioides stat. nov. A

A. gracile/boranense A. gracile/boranen.se

B

Totally glabrous cypselas; leaves pinnately veined; young capitula with conspicuous subtending bracts. Small glomerules; lateral glomerules; leaves basally palmately veined. Pedunculoid branches lacking. -

in fairly humid escarpment forests in Kenya, down to dry, open grasslands at the base of the escarpment 500 m lower. Those specimens are still very similar. In the case of A. borunense, there may be some clinal variation although within the species. 27ze gracile/hastifolium intermediates Athroisma grucile in a wide sense is distributed from northern Kenya in an arc to north-eastern Tanzania (Figs 13, 37). The distribution area is more or less centred on the border between Kenya and Tanzania, and has a curious disjunction in the middle around Lake Natron. The collections have in most cases been made in the close vicinity of the main roads in the area (Fig. 13). Due to the fact that the distribution seems to follow roads, the scattered distribution pattern is assumed to be mostly an artefact of collection and thus extrapolated to include all collections (the marginal line in Fig. 13). All the maps in Figs 13-16 and 20 are extrapolated in this manner. The distribution of A. hastifolium is found completely within that of A. grucile (e.g. Fig. 14). Collections labelled A. p.$Zioides or A. haareri always have more or less wide leaves with marginal teeth, intermediate between A. grucile and A. hastifolium. Another striking character is the cypsela surface which is almost smooth within the genus, except for A. hastifolium in Mihich rugose or strongly tuberculate cypselas are found. This character was also found in collections determined as A. psyllioides and A. haareri, often in close vicinity of A. hastifolium. Several characters were studied and correlated to geography. Maps were compiled (Figs 14- 16) in which the mean values for the character were

T. ERIKSSON

128 2” N 34” E

ro

1

40” E

6” S Figure 13. Distribution of Adroima gracile in a wide sense with indicated. The dark grey areas are where specimens have actually 37). The light grey area is the extrapolated approximate distribution

plotted and lines were drawn The maps show that: (a) In the studied

characters

much

like

isobars

the area (cf. Fig.

on a meteorological

A. grucile approaches of that species.

A. hastifolium in the vicinity

main roads in been collected area.

map.

the character states of This would support a

hypothesis of introgression. (b) The same character states are also found away from the south-eastern part of the distribution area.

A. ha.stifoZiumin

Scatter diagrams (Anderson, 1949) were used to investigate some of the characters. Specimens of A. gracile were divided into two classes, one class (A. grucile s. str.) with completely smooth cypselas, and one class (intermediate)

THE

GENUS

ATHROfSM4

129

0

>lO

I

smooth

m

overlap

_

overlap tuberculate to rugose

@@j

A. hast

m

2.5-10

~

A hast
Figure 14. (Left) Geographical specimens of Athroisma grucile.

distribution The hatched

of the quota of leaf area is the distribution

length by leaf width area of A. hastijblium

in

(A.

had.). Figure

1.5. (Right)

Geographical

Athroisma grucile. The hatched

distribution of the cypsela area is the distribution area

surface of A.

character

in specimens

of

hartifolium.

with tuberculate to rugose cypselas. These were compared with the specimens of A. htitifolium. A. pacile (with smooth cypselas) and A. hastifolium are well separated in the diagrams (Figs 17A & 18A). When the intermediate class is added (Figs 17B & 18B) its collections fill the distance between the previous groups. The geographic distribution of these characters and the scatter diagrams support the notion of hybridization with subsequent introgression into A. gracile: characters from A. hastijdium are seen in A. gracile in the vicinity of A. hastifolium. There are fewer indications of introgression into A. hastifolium. The leaves of some collections lack the hastate or truncate bases characteristic of A. hastifolium, being more or less cuneate. This might indicate introgression. The polymorphism of A. hastifolium in the cypsela surface character may also be an indication of introgressive hybridization where gene flow has occurred from A. Facile into A. hastifolium. Other characters do not show intermediacy. A. gracile is glabrous while A.

3 v

,,

.:

‘,..

:/)

8

THE

GENUS

ATHROISMA

131

80 A

L

I

I 2

0

4

AA4

AA4

AA

4

h&A

,A

i

6

8

6

8

80 B

60 t

0

2 Number

4 of leaf margin

teeth

Figure 17. Scatter diagram of Athroisma grucile (0) and A. harbjilium (a). The number leaf margin teeth on the horizontal axis. The quota of leaf length by leaf width on vertical axis. A, without intermediates; B, with intermediates (0).

of the

hastifoli~m is pubescent, gland dotted and has glandular hairs- (a single specimen of A. gracile: Bally 73774 has short glandular hairs); A. gracile always lacks female florets while such are present in each capitulum of A. hastifolium; the dry persistent leaves at the stem bases of A. hastifolium are not seen in A. Facile. Taxonomically this situation has resulted in three species being described: A. gracile, A. psyllioides and A. haareri, of which the two latter are based on intermediate collections. If the intermediate specimens were present only in the near vicinity of A. hastifolium, I would choose to treat them simply as ‘hybrids’ even though they may be common. However, since most of the south-eastern part of the distribution of A. gracile, where its characters comply with A. p.sy1Zioide.s (Figs ’ 14-16), occurs well away from A. hastifolium, and since there is an area in which A. psyllioides gradually turns into A. gracile (senru stricto), I find subspecies rank reasonable: A. gracile ssp. gracile for the

T. ERIKSSON

132

1 A

A A

c

A

A A

AA

A

AA A A

A

A I

I

2

4

I

I

I

8

6

0.5 B

A

.

A

A A

A A

A

A A

A

A

AA AA

A A A

I 0

I 2 Number

I 4 of leaf margin

I 6

8

teeth

Figure 18. Scatter diagram of Athrotmm gmcile (0) and A. hmfiflium (A). The leaf margin teeth on the horizontal axis. The quota of the length of the pedunculoid by the total height of the plant on the vertical axis. A, without intermediates; intermediates (0).

number of branches B, with

strict A. gracile in the north-west with smooth cypselas, and A. gracile ssp. psyllioides for the intermediates with tuberculate to rugose cypselas in the centre of the area of distribution and to the south-east. When analysed cladistically (Fig. 12) the subspecies are interpreted as sister taxa, which the parental species are not. The gracileboranense intermediates Athroisma boranense is a plant of the southern Ethiopian mountains (Sidamo region, Fig. 26). It is found in relatively high elevations and is, in those localities, easy to distinguish on the sessile, elliptic, usually toothed and hairy leaves with glandular hairs and an almost flat or revolute margin, and the presence of female florets. A. pracile ssp. gracile (as delimited above) is distributed in central Kenya and into the dry parts of northern Kenya but not close to the foothills of

THE

GENUS

ATHROISMA

133

the Ethiopian mountains where A. boranense is found. It is distinguished from A. boranense by its narrow, almost entire, glabrous leaves with involute margins, and the lack of female florets. In northern and north-eastern Kenya (Fig. 28) scattered specimens have been collected (subsequently called group A) which approach A. grade in general appearance and seem to share characters from both species. They have rather narrow leaves like A. grade which are toothed, gland-dotted and hairy-more like those of A. boranenre, although more thinly hairy. In addition, most of them have female florets, and some of them have glandular hairs like A. boranense. Some from the vicinity of Nairobi (Athroisma sp. A sensu Agnew (1974)) h ave slightly narrower leaves and are almost without hairs. The group A is quantitatively intermediate in leaf width, number of leaf margin teeth, hairiness, and (less distinct) in direction of leaf margin. As seen in the scatter diagram (Fig. 19A) A. grade (in strict sense) and A. boranenre (in strict sense) are well delimited on the basis of two quantitative characters. Group A falls mostly in between, spanning the-gap between the two species (Fig. 19B) although the pattern is not strictly continuous. A more mosaic pattern is evident in the presence of glands on the leaves, and the pubescence of both types. Some intermediates are devoid of hairs like A. gracile, and other intermediates have normal hairs, glandular hairs or both like A. boranense. A few collections from central Tanzania (Serengeti Nat. Park and Mt. Hanang, subsequently called group B) have narrow, short and rather stiff leaves (due to the margins being strongly involute) which are only slightly hairy, although glandular. They lack female florets and are rather similar to A. grade (Fig. 19C) but are less branched, and the basal leaves seem to remain when dry. These intermediates are geographically separate, and it is perhaps not logical to treat group B as the result of hybridization between A. boranense and A. gracile when one of the parental species is so far removed, and on the ‘wrong’ side. It might be treated as an intermediate species but, like in group A, the characters vary within the group making it heterogeneous. I find it premature to describe a new species based only on those few intermediates especially since they lack autapomorphies, and indeed have hairs on the leaves which are very similar to some specimens of group A. To conclude about these two intermediate groups: I do not given them any rank due to their being heterogeneous and explainable as being of hybrid origin. The collections are cited under A. boranense. Scenario In what way could these character patterns have emerged? It seems that some characters have been ‘seeping’ into A. gracile from A. hastifolium via introgressive hybridization. When introgression occurs one might expect a character pattern like the one found, with the exception that the seepage of characters found is geographically one-sided: characters from A. hastifolium have ‘seeped’ more towards the southeast than in other directions. One explanation might be that hybridization has, for unknown reasons, occurred more often near the south-eastern limit of A. hastifolium than in other areas, and the characters

T. ERIKSSON

134

40

20

0

60

80

60

80

10 B c %

8-

A A

8

,

Gill&t and Kibuwa 19998 Gilbert and Thulin 1234

20

40

20

40

-AA l? -A

h

Leaf

I

60

0

I

80

length/width

Figure 19. Scatter diagram of Alhroirma grucile (0) and A. boranense(A). The quota of leaf length by leaf width on the horizontal axis. The number of leaf margin teeth on the vertical axis. A, without intermediates; B, with intermediates of group A (A), some collections are indicated; C, with intermediates of group B (0).

THE

GENUS

ATHROlSMA

135

Figure 20. Distribution scenario. The dark grey area is Athroisma grucile, and the lighter grey area is A. botanense. A, A. gracilt in an allopatric position West of A. boraneme. B, the present dish-ibution. The medium grey areas are those affected by hypothesized introgression.

then ‘seeped’ into an already present A. grucile. Another explanation, which I find more likely, is that A. gracile has spread towards the southeast, from an allopatric position, into the distribution area of A. ha-stifolium. Affected by introgressive hybridization it then continued to spread towards the southeast. I favour the dispersal hypothesis because of the presence of wide-leaved specimens, with many leaf margin teeth and rugose cypselas, quite far from the distribution of A. hastifolium; it also satisfactorily accounts for the intermediates between A. grucile and A. boranense (see below). In addition, I know of no differences in habitat preference in these two species, and it is unreasonable that they have originated sympatrically during extensive hybridization. On the ‘other hand, it seems reasonable that the species have started out allopatrically and also that A. gracile has entered into the area of A. hastifoolium. The intermediates of A. gracile and A. boranense may be explained by the same scenario. Two hypotheses are required: (1) that the previous distributions of A. gracile and A. boranense (sensu Z&o) are allopatric with distributions something like those in Figure 20A and (2) that the species are capable of hybridization and introgression. Initially A. g-rucile is dispersed into, and through, the distribution area of A. borunense (Fig. 20B) and hybridization with subsequent introgression takes place. Group B is thereby sealed off from the rest of A. borunense and changed through introgression, acquiring some characters from A. gwile. Group A also changes through introgression, giving a character pattern more or less gradually changing from A. g-racile to A. boranense in the north, but with a mosaic pattern. If the above scenario is accepted, it seems possible that A. hastifolium is

T. ERIKSSON

136

0

z

Number Figure 21. Scatter diagram , The number of leaf margin on the vertical axis.

Cl

4

of leaf margin

of Athroimza gracik (O), teeth on the horizontal

teeth

A. stuhlmannii (O), and A. inevitabile (m). axis. The length of pedunculoid branches

also involved in the intermediates of group A, at least in the south. One specimen quite far removed from the Ethiopian mountains (Gillett @ Kibuwa 79998, Fig. 28) has wide leaves which are very similar to those of A. borunense, except for the presence of a petiole, a character of A. hustifolium, which may be present also in other specimens in group A, although this is hard to observe in narrow leaves.

intermediates Athrotima stuhlmannii is distributed from the eastern side of Lake Victoria,

The gracile/stuhlmannii

Kenya, through western Tanzania and, in a scattered fashion, to northern Zambia (Fig. 39). It is a distinct species diagnosed by the autapomorphic lack of pedunculoid branches, i.e. the glomerules are sessile at the nodes. Some collections from Uganda and Rwanda are similar to A. stuhlmannii in many characters as well as to A. gracile, but they are annual like A. stuhlmannii, and are also found in wet habitats. They have pedunculoid branches almost intermediate between A. stuhlmannii and A. gracile (Fig. 21), and one specimen from Uganda seems to be a rhizomatous perennial. The distribution does not support a hybridization hypothesis in this case since the group is allopatric rather than geographically intermediate. It is simpler to interpret the intermediate group as an intermediate taxon. The typical grade of short apical pedunculoid branches and longer basal ones is a probable autapomorphy. The absence of intermediate collections from the area where the two species actually meet (southeast of Lake Victoria, Fig. 39) indicates that A. stuhlmannii and A. grucile do not hybridize. This fact supports the above interpretation. Athroisma stuhlmannii and the intermediate group are shown in the cladistic analysis to be sister groups (Fig. 9) and in this case I would choose subspecies rank if they graded into one another-which they do not. If more collections from the geographic area in between A. stuhlmannii and this group are found to be intermediate, subspecies might be the proper rank. With the material

THE

at hand, however, of A. inevitabile.

GENUS ATHROISMA

the only applicable

137

rank is species, and hence the erection

TAXONOMY

Athksma De Candolle

(1833:

516). Type:

Polycline Oliv. (1894: t. 2293). here (= Athroisma gracile (Oliv.) Etheocephalus Gag-r-rep. (1920: (= Athroisma Zaciniatum DC.).

Athroisma

DC. Zaciniatum

DC.

Typ e: Polycline gracilti (Oliv.) Oliv., Ma&f.). 172). Type: &theocephaZus thorelii

selected Gagnep.

Erect c. 10 cm-2 m high perennial herbs to subshrubs or shrubs (?), or erect to prostrate 5-c. 80 cm high annual herbs. Stems and branches glabrous to tomentose, glandular or eglandular, yellowish green to green, becoming brownish to reddish brown or pinkish and glabrous. Rhizome present or absent. LEAVES petiolate or not, pubescent to glabrous, glandular to eglandular; one-veined, basally three-veined or palmate, or penninerved. Lowermost leaves remaining when dry or not. LAMINA entire, incised or pinnatifid, linear to ovate or obovate, or almost triangular 1.5-12 x 0.1-7.5 cm, chartaceous to coriaceous; apex acute to acuminate or obtuse, apiculate or not; margin entire to serrate or dentate, revolute to involute, ,glabrous to pubescent, some with l-2 mm long hairs basally; base attenuate to truncate, hastate or cordate; veins usually prominent on lower side and lighter than lamina; teeth when present fapiculate; lobes when present 3-7, subopposite, often narrowed at their bases, 1-15 mm wide. Petiole absent or up to 32 mm. Upper leaves reach the glomerules or c. 0.5-21 cm below the glomerules, gradually diminishing or of normal size. S~NFLORESCENCES one or dichasial, of 2-10 (30) glomerules, some simple; branches slender or robust, pubescent or glabrous. GLOMERULES spherical to semi-spherical or ellipsoidal, 5-25 mm wide, the ellipsoidal ones lo-30 mm long containing 8-65 white, creamy white or yellowish capitula, often with a pinkish or purplish tinge. CAPITULA 2-5 mm wide, with or without two female florets, with 4-45 hermaphrodite florets. BRACTS obovate to widely ovate (triangular) or lingulate; apex acute to acuminate; margins entire or slightly dentate, flat, or apically involute, &ciliate, hyaline or not; pubescent and glandular or eglandular, or glabrous. Median bracts 2-5.5 x l-2.5 mm. Basal bracts 2-6 x l-4 mm. INVOLUCRAL BRACTS absent or two, narrowly elliptic to obovate, 3-5 x 1.5-3 mm; apex obtuse; margin ciliate, widely hyaline; pubescent and some glandular, or glabrous. PALEAE obovate to elliptic, rectanguloid or ovate, 2-5.5 x 1-4 mm; apex obtuse * to truncate, erose to three-lobed, ciliate; abaxial side with a few hairs, glabrous or glandular. FLORETS white or slightly pinkish with green tube. COROLLA of female florets 1.5-2.5 mm, indistinctly or distinctly widened at apex, glabrous or glandular. COROLLA of hermaphrodite florets infundibuliform to campanulate, 4 or 5-lobed, 1.5-3.5 x l-2.5 mm, glandular; tube glandular or glabrous. Anthers 0.8-2.2 mm; apex acute, some slightly apiculate; tails 0.1-0.4 mm. Style 1.5-3.5 mm. CYPSEWS elliptical, ovate to obovate, slightly obcordate, or almost circular in outline, f dorsiventrally flattened, not or

138

T. ERIKSSON

Figure 22. Known distribution

of the genus A&hroina

slightly more narrow near middle, l-3 x 0.5-1.5 mm, glabrous or with twinhairs&evenly scattered and/or distinctly along the lateral ridges, glandular or eglandular; lateral ridges distinct or indistinct; surface smooth, tuberculate or mgose; twin-hairs ~0.1-0.5 mm, with recurved, diverging or almost straight apical branches; pappoid corona scale-like, with very narrow semi scale-like projections, as a ring of basally connected twin-hairs, or absent; neck O.l0.2 mm. Receptacle 2-7 mm. The genus is distributed in eastern Africa, on Madagascar, and (one species) from north-eastern India to the Sunda Islands (Fig. 22). In general, the species are herbaceous perennials or annuals found in grasslands, scrublands, savanna, or as weeds of cultivation. The annuals are mostly found in seasonally wet areas, and the perennials in wet or dry to semi-desert conditions. KEY TO THE SPECIES 1. Leaves with gland dots (usually most dense on lower surface); leaf margin revolute to involute .......................................................................................................... ... .... .......................... 2 2. Leaves with biseriate glandular hairs ............................................ ..... .. ..... .......................... 3 3. Leaves distinctly petiolate ........................................................... ..... .. ... ............................ 4 4. Leaves narrowly triangular; glomerules 5-9 mm wide .. .. ... .. ........ 6. A. @sillurn 4’. Leaves widely triangular to obovate; glomerules 13-20 mm wide ..................... ...............................,................................................................... .. ... .. ......4. A. hastiflium 3’. Leaves sessile or indistinctly petiolate .................................... .. ... .. ............................... 5 5. Leaves with uniseriate hairs, biseriate glandular hairs, and gland dots; female florets present ........................................................................... .. .. ........... 3. A. boranenre 5’. Leaves lacking one or more trichome types; female florets present or absent ................................................... intermediates between A. boranenre and A. Facile 2’. Leaves without biseriate glandfrlar hairs .............................. .. .. .... .. .. .................................. 6

THE

GENUS

ATHROZShh4

139

6. Leaves distinctly petiolate; leaves incised or lobed.. .................................................. 7 7. Leaves incised, sometimes very shallowly.. ............................................................. 8 8. Corolla of hermaphrodite florets four-lobed; female florets present.. .............. ........................................................................................................... 1. A. laciniatum 8 . . Corolla of hermaphrodite florets five-lobed; female florets absent.. ............ 9 9. Bracts subtending capitula leaf-like; involucral bracts absent; cypselas glabrous.. ................................................................................. .5. A. psilacarpum 9’. Bracts subtending capitula not leaf-like; involucral bra& present; cypselas with twin hairs at least along lateral’ridges ........................... 2. A. lobatum 7 .. Leaves deeply (and mostly narrowly) lobed, rarely unlobed.. ......................... 10 10. Leaf lobes O-3; pappoid corona wide and scale-like.. .........8. A. proteifone 10’. Leaf lobes 3-7; pappoid corona with narrow, not scale-like, projections .................................................................................................. 7. A. pinnatipum 6’. Leaves indistinctly petiolate; leaves entire.. ......................................................................... .............................................................. intermediates between A. boranense and A. grade 1’. Leaves without gland dots; leaf margin involute (almost flat in wide leaves). ........... 11 11. Leaves with uniseriate hairs..........intermediate s between A. boranense and A. gracile 1 1.. Leaves glabrous.. ............................................................................................................... 12 12. Cypselas slightly longer than the corolla; leaves linear.. .......... 10. A. fanshawei 12’. Cypselas much shorter than the corolla; leaves linear to elliptic or ovate ...... 13 13. Herbaceous annuals; synflorescences at least apically monochasial............ 14 14. Pedunculoid branches absent.. ...................................... 11. A. stuhlmannii 14 ‘. Pedunculoid branches present but short near shoot apex.. .................. ............................................................................................ 12. A. inevitabile 13’. Rhizomatous perennial herbs; synflorescences dichasial, or glomerules single in the shoot apices.. .............................................................................. 15 15. Cypselas smooth; leaves l-5 mm wide.. ........9a. A. gracile ssp. grade 15 .. Cypselas tuberculate to rugose; leaves l-25 mm wide.. ....................... ......................................................................... 9b. A. grade ssp.psyllioides

Athroisma laciniatum (Figure 23) De Candolle (1836: No. 3184) - Type: selected here).

369). Wallich

DC.

Sph aeranthus laciniatus Wall. 294, Trogla in Martabania

nom. nud. (1831: (G-DC lectotype,

Athrotima-viscidum Zoll. & Moritzi (Zollinger, 1845: 232). (‘viscida’)-Type: Zollinger 2744, In orycetis exiccatis prope Gunung Saharie Pago Surabaja VII. 45 (BR lectotype, selected here; P duplicate). Btheocephalus thorelii Gagnep. (1920: 172). - Type: Godefioy (in Herb. Pierre N” 6503) 277, Cochinchina, in ins. Phu Quoc (P lectotype, selected here). Flora references. Clarke (1876), Hooker (1881), Kooders (1912), Backer & Bakhuizen van den Brink (1965). Notes. De Candolle did not describe any species along with the description of the genus Athroisma (1833: 516). He merely stated: “Ce genre est fondi sur une @ante de l’lndie orientale dkouverte par M. Wallich, et que ce savant dkipait dans ses collections sous le riom de Sphaeranthus laciniatus” (Cf. Art. 33.1. of the code (Greuter et aL, 1994)). He later described Athroisma laciniatum in the Prodromus (Candolle, 1836).

T. ERKSSON

140

6

C

D

E

F

G

Figure 23. Athroirma laciniatum Al, flowering branch; A2, ellipsoid glomerule; B, basal subtending bract; C, median subtending bract; D, involucral bract; E, female floret; F, palea; G, hermaphrodite floret; H, twin hair; I, anther (Al Dulla 505; A!& E, G, I Grzjiilh 905; B, C Kurz 848; D, F Zollinger 2744; H Kerr 5669). Scale bars: A = 1 cm; B-G = 1 mm; H = 0.1 mm; I = 0.5 mm.

The collection by Wallich to which De Candolle refers in the Prodromus is no longer present in the Wallich Herbarium at Kew. In the Prodromus Herbarium at Geneva (G-DC), however, two specimens are present which I think might both have been collected by Wallich at that time. One bears Wallich’s number 294 and the locality mentioned above. The other has the number 1872 and the locality “Trogla 12/7-27”. De Candolle writes (1836: 369): “Spaeranthus laciniatus Wall.! cat. n. 3184. camp. 294. cat birm. 1872. (v.. s. comm. ab. ill. Cur. mere. angl. Ind. or.)“. The number on Zollinger’s collections of Athroirma viscidurn (2144) seems to have been a species number rather than a collection number. Different

THE GENUS ATHROISMA

141

localities and collection dates are found on the various specimens even though the number is the same. I have accepted as types only those explicitly stating the same locality given in the original publication. Other specimens with the same number include: Ins. Sumbawa (BM, G, L, P); Jawa, without precise locality (BM, G, M, P, W). Gagnepain (1920) cited several specimens when he described ktheocephalus thorelii. Two of these, collected by Godefroy, bear the same number although they apparently are from different localities. The number 217 is cited only once by Gagnepain but is also present on the specimen I selected as lectotype. Autapomorphies not mentioned in description: hermaphrodite florets fourlobed and with four stamens; stems inflated, rooting freely when prostrate; sides of paleae adnate at base. Erect, spreading or prostrate annual herbs, 5 up to at least 40 cm high. Stems and branches glabrous to tomentose, green, becoming brown to reddish brown and almost glabrous. Rhizome absent. LEAVES petiolate, pubsescent to almost glabrous, glandular (mainly on lower side), basally three-veined. Lowermost leaves not remaining when dry. Lamina+ deeply incised, more so towards base, ovate to obovate, c. 4-9 x 2-3.5(-5) cm, chartaceous; apex obtuse, apiculate; margin serrate to dentate, frevolute, glabrous; base attenuate; teeth apiculate; lobes 3-4, subopposite, often narrowed at their bases, rarely secondarily incised, 3-lO(-15) mm wide. Petiole 8-25 mm. Leaves reach 3-38 mm below the glomerule, of normal size. SYNFLORESCENCES monochasial or dichasial, of 2- c. 9 glomerules; branches rather robust, pubescent to glabrous. GLOMERULES lo-20 mm wide, containing 35-60 white capitula. CAPITUW 3-4 mm wide, with female florets and 19-45 hermaphrodite florets. BIWCTS ovate (median) to triangular (basal); apex acute to acuminate; margins flat, sparsely ciliate, hyaline part wide; both sides glabrous. Median bracts 3-4 x 1.5-2 mm. Basal bracts 3-4 x 1.5-2.5 mm. IWOLUCRAL BFCACTS obovate, 3-4 x 1.5-3 mm; apex obtuse; margin sparsely ciliate, widely hyaline; both sides glabrous, or with a few hairs abaxially. PALEAE obovate, 2.5-4 x 23 mm; apex obtuse, obscurely three-lobed; abaxial side glandular basally. COROLLA of female florets 1.5-2 mm, widened at apex, glabrous or with a few glands. COROLLA of hermaphrodite florets 1.5-2 x 1 mm; tube usually glabrous.-Anthers 0.9 mm; tails 0.1-0.2 mm. Style 1.5 mm. CWSELAS elliptical in outline, not narrow near middle, 1.5 x 1 mm, with dense marginal hairs and .a few scattered hairs mainly near base, eglandular; lateral ridges (in?)distinct; surface smooth; twin-hairs 0.1-0.3 mm, with recurved apical branches; pappoid corona scale-like with the lateral scales longer; neck c. 0.1 mm. Receptacle 3-7 mm. Distribution and habitat Athrotima laciniatum is the most widespread species in the genus (Fig. 24): It has been found in a scattered distribution, describing an arc from Assam in India to the island of Sumbawa east of Java in Indonesia. The pattern of collected specimens suggests gaps in the area of distribution (in north-eastern Burma, and from southern Thailand through Malaysia to Sumatra) but it is unknown whether these are simply artefacts of collection. According to

T. EEUKSSON

142

Figure 24. Known localities.

distribution

of Athrozhu

hciniulum

Unfilled

circles

denote

approximate

Gagnepain (1920) it has also been found in Laos, although no collections are cited. It is found in wet (or dried-out) areas: beaches, stream sides, watering channels (and ditches), or dry rice fields (sazerah). Sand or clayey soil have been indicated, and altitudes from sea level up to c. 200 m. Locally common. Notes This species is readily recognized by its ‘inflated’ stems and branches together with the deeply incised, toothed leaves. Similar leaves are found also in A. Zobatum but that species differs in not being an annual, has fivelobed rather than four-lobed corollas, and lacks the female florets present in A. Zaciniutum. Most specimens seem to be branched mainly at base. The variation in A. laciniutum is rather limited even though the species similar in ranges over a large area. All studied specimens are remarkably the florets and the scales within the glomerules. The leaves are more or less deeply incised but this seems to be more related to the size of the specimens. There is a geographic pattern to the variation in hair covering in that most specimens from India, Burma and Thailand are less hairy than most specimens from Java and adjacent islands. Another character which is variable is the Some specimens have nicely spherical glomerules form of the glomerule. while others have ellipsoidal glomerules of various lengths (up to 3 cm). No distinct geographical pattern is apparent, but specimens with spherical

THE GENUS ATHROISMA

143

glomerules in the Java area are as numerous as the ellipsoidal ones, while completely spherical glomerules have not been found in India. Collections examined (56) INDONESIA, NUSA TENGGARA BARAT: Sumbawa, Dompu, ZoZZinger 2744 (BM, G, L, P). JA\~A TIRJUR: Gresik-Lamongan road, east of dry watering channel along rice field, 2.x.1929, Coert 796 (A, L). Surabaya, Gunung Sahari, Naphta Wells [fide Zollinger (1845). cf. van Steenis-Kruseman (1950)], vii.1845 ZoZZinger 2744 (BR, P). Surabaya vicinity [fide van Steenis-Kruseman (1950)], 1819, Perrottet s.n. (P) Bolongbendo on the main road close to Bangil, 31.vii.1923, Kooper 504 (L). Sugar factory Bolongbendo near Krian, alt. c. 15 m, 15.vi.1915, uan Laterick s.n. (L). Bangil, 13.xi.1928, van Slooten 2076 (A, K, L). Pasuruan, alt. 3 m, 18.x.1927, Backer 36793 (L); alt. 4 m, 24.xi.1930, Backer 36732 (L). JA\VA TENGAH: Koewoe-Randoeblatoeng, ah. 50 m, 1913, Backer 6583 (L). Kedungdati, 18.ix.1896, Koorders 257778 (K, L). Semarang, HorsJieZd s.n. (BM, K); Boedjanggoet s.n. (Herb. Lugd. Bat. 900,743-744) (L). Kendal, alt. 2 m, 1914, Backer 76395 (L, P). Tegal, alt. l-5 m, 1914, Backer 75232 (L). Brebes, alt. 5 m, 1914, Backer 75329 (L). JA\\:A BARAT: Cirebon, alt. 5 m, 1912, Backer 4707 (L). Uncertain localities Jawa: Labillurdiire s.n. (G); Laffay s.n. (G); Zollinger 2744 (A, BM, G, M, P, W); ZoZZinger s.n. (G, GH, L). VIETNAM: Quan Phu Quoc, Godefioy in Herb. Pierre 2 77 (P). CAMBODIA: Fields at Kompong Chhnang, 6.vi.1875, Godefioy 277 (P). Babo village, on the small lake, vi.1875, Godefioy 277 (K). Mekong, Kompong Luang, 186668, Thorel 2068 (P). Without locality: Godefioy (voyage Dr Harmand) s.n. (P). THAILAND: Tha Duang, Muang Petchabun, alt, ca. 200 m, 4.iii. 1931, Kerr 20363 (BM, K). Muang Phichit, alt. c. 50 m, 25.iii.1922, Kerr 5664 (BM, K, P). Palanam Senglaram, Nakhon (Nakuun) Param (?), alt. c. 200 m, 7.v.1932, Kerr 27358 (BM). BURMA, K\REN STA.E: Salween river at Trogla, WaZZich 294 (G-DC). Trogla, 12.vii.1827, WaZZich ? Burm. cut. 1872 (G-DC). MAIVDALAY: Pyinmana (Pinmona), 24.viii.1890, Huk s.n. (G) PEGU: 21.i.1871, Kurz 2227 (CAL); 1860?, LeZZand 745 (BM, P, W). Banks of Sitang, Kurt 848 (CAL,). Meaday, Scott s.n. (L, M). Rangoon, LeZZand s.n. (K) TENASSERIK Tenasserim and Andamans, Leimbae, He@ East India Herb. 3727 (CAL, GH, K, P). INDIA, Ass:nr: Unknown localities: GrzJith East India Herb. 3727 (CAL, P). 1829, GrifJith 905 (N473) (BM, K). Grz$th s.n. (CAL, GH, P). iii.1875, Kuntze s.n. (K). MEGHALAYA: Nongpoh, iv.1893, Dr. King’s Collector s.n. (CAL). Assam and Kha; Hills, Simmon s.n. (L). WEST BENGAL: Maldah, 30.iv.1875, Clarke 26304 (K). Bhaluka rd, 26 .viii.1966, Duttu 505 (CAL). Calcutta vicinity, 183638, He&% 789 (BM, BR, E, G, GH, L, S); 1836-38, He@ 376 (CAL). Unknown localities: Falconer 559 (K). India orientalis, 1836-40, He& 365 (M); He@ s.n (P, W). Gourhan, Hooghly, 9.vi.1963, Prabhat 309 (CAL,). BIHAR: Rajmahal, Beddome 4397 (BM). Bhagalpur, Along the base of the Rajmahal Hills near Maharajpur (Maharaj Pore), v.1867, Kurz s.n. (K); Gangetic Delta, River Gandak near Patna, i.1857, KZatt 72939 (GH). Athroisma

Zobatum (Klatt) (F&we 25)

Mattf.

Mattfeld (1936: 301). - BZph e art ‘p ermum Zobatum Klatt (1895: 428). - PoZycZine Zobata (Klatt) Chiov. (1931: 354). - Type: Keller 6, Somaliland, Webi Suabeli, 1891/92 (Z holotype, GH isotype).

T. EIUKSSON

Figure 25. Athroima lobatum. A, flowering branch; B, basal subtending bract; C, median subtending bract; D, involucral bract; F, palea; G, hermaphrodite floret; H, twin hair; I, anther; J, Leaves (A, B, D, F, G, I Confalone 56; C C$rri 98; H Bully 70173; Jl Hansen 6070, J2 Semi 744). Same scale as in Fig. 23, scale of J = A.

THE

GENUS

ATHROISM4

145

Illustration Chiovenda (1932, fig. 152). Flora reference. Chiovenda (1932). Autapomorphies not mentioned in description: crystal druses in corolla tube bases (rarely also in A. proteiforme and A. PinnatiJidum); presence of empty involucral bracts. Erect 20 to more than 40 cm high, perennial herbs with somewhat woody bases. Stems and branches pubescent, yellowish green, becoming yellowish brown and glabrous. Rhizome present. LEAVES petiolate, pubescent, glandular (mainly on lower side), basally three-veined. Lowermost leaves not remaining when dry. Lamina entire to deeply incised, more so towards base, ovate to obovate, 1.5-9 x l-5 cm, + coriaceous; apex obtuse, apiculate; margin dentate, slightly revolute, pubescent; base attenuate; teeth apiculate; lobes O-3, subopposite, often narrowed at their bases, not secondarily incised, 1-14 mm wide. Petiole 4-23 mm. Leaves reach 15-60 mm below the glomerule, of 2-7 glomerules; gradually decreasing in size. SYNFLORESCENCES dichasial, branches robust, pubescent. GLOMERULES lo-19 mm wide, containing 30-65 white to pinkish capitula. CAPITUA 2-4 mm wide, without female florets, with 4-l l(-20) h ermaphrodite florets. BRACTS lingulate or narrowly ovate to narrowly elliptic; apex acuminate; margins flat, sparsely ciliate, hyaline part wide; abaxial side pubescent and glandular to almost glabrous; adaxial side glabrous. Median bracts 2.5-5.5 x l-2 mm. Basal bracts 4-6 x 2 mm. INVOLUCIWL BRACTS elliptic to narrowly elliptic or narrowly obovate, 3-5 x 1.52.5 mm; apex obtuse; margin ciliate, widely hyaline; abaxial side pubescent and glandular; adaxial side glabrous. PALEAE obovate to elliptic, 4-5.5 x 2.53.5 mm; apex obtuse, obscurely (mostly three-) lobed; abaxial side glandular. COROLLA of hermaphrodite florets 2-3 x 1.5-2 mm; tube usually glabrous. Anthers 1.3-1.7 mm; tails 0.2 mm. Style 2-3(-3.5) mm. CYPSELAS slightly obovate or elliptical in outline, not narrow near middle, 1.5-2 x 1 mm, with marginal and scattered hairs, eglandular; lateral ridges distinct; surface smooth; twin-hairs 0.1-0.2 mm, with recurved (or ascending) apical branches; pappoid corona as a ring of basally connected hairs, in a few collections extended laterally; neck 0.1-0.2 mm. Receptacle 2-4 mm. Distribution and habitat Athrotima Zobatum is distributed the eastern part of the Harerge Ethiopia (Fig. 26). It is reported It is found in scrub savanna of water holes or saline water, found on saline or gypsum soils, Altitudes range from less than Ethiopia. Collected in flower between October and January.

from near the coast in central Somalia to region (and maybe also the Bale region) in to be common locally. with grasses, in wet habitats like the vicinity or as a weed in cultivated fields. It has been together with Euphorbia, Sueda, and Limonium. 100 m near the coast up to c. 1000 m in from May to February, in most instances

Notes It is distinguished from other species by the wide, usually dissected petiolate leaves with attenuate bases and blunt apiculate teeth. In some cases the

T.EEUK.SSON

146

Figure 26. Known denote approximate horn of Africa.

distribution localities.

of Athroima lobatum (0) and A. boranense (m). Unfilled The map shows a section of the East African coast

symbols with the

leaves are more or less entire (Fig. 25’Jl). and A. Zobatum is distinguished from A. hastifolium in those cases by the blunt teeth and the lack of female florets. Other species in the genus have dissected leaves: A. Zaciniatum which differs by being an annual, and by having female florets, and A. proteiforme and A. pinnatzjidum which have narrowly and deeply lobed leaves, often with filiform lobes. Vernacular names: Dup-addi (Shabeelaha Hoose); Furbunole (Shabeelaha Dhexe). Collections examined (19) SOMALIA, NUGAAL: Xudun-Xalin rd, 25.x.1944, Glover &5’ Gilliland 235 (K). Near Laascaanood, ah. 750 m, 24.ix.1952, Hemming 189 (EA, K). Laascaanood grazing reserve, dt. 725 m, 23.x.1954, Bally 70773 (EA, K). TOGDHEER: Depression 25 km N of Oog, 9”lO’N 45”45’E, ah. 400-600 m, 21.vi.1979, Hansen ES’ Heemrtra 6204 (C, EA). MUDUG: 2.5 miles SE of Xinduugen (Hundughery), c. 6”30’N 47”45’E, xii.1961, Paskin H779 (EA). East of Ghelinsor, near temporary waterhole, ah. 275 m, 5.ii.1954, BaZb 9594 (EA, G, K). HIIRAAN: 10 km NE of Buulobarde, ah. 175 m (600 m?), 25.xii.1972, Bally &’ Melville 75327 (EA, K). 2.5-3 km NE of turning to Jalalaqsi on Buulobarde rd, 3”26’N 45”31’E, ah. 125 m, 22.v.1989, Thulin &’ Duhir 6404 (UPS). SHABEELLAHA DHEXE: Mahaddayweyne, 6.x.1922, Confalone 56 (F'T). SHABEELLAHA HOOSE: Basin of Webi Shabeelle, Afgooye, 22.x.1934, Cifewi 98 (FT, K). Agriculturad Research Station 26 km W of Mogadishu

THEGENUS

ATHROISMA

147

near Afgooye,

17.vii.1979, Hansen 6070 (EA, K). Jannaale, 20.x. 1935, Bigi 15 Xuddur, 17.viii.1929, Senni 744 (IT). BAY: 86 miles N of Baraawe, ah. 100 m, 30.i.1954, BaZZy 9.528 (EA, G, K). Uncertain locality: ‘Guelidi sur le fleuve Ouebi’ [not Webi Shabeelle (Engler, 1904; Chiovenda, 1916)], vii.-ix.1883, Revoil s.n. (P). - ETHIOPIA, HARERGE: Wabe Shebele Wenz at Maadiso Shet’ (Ueb Karanle), 24.i.1893, Riva 7035 (442) (FT). Sheneli (Schinile), 26.xi.1972, Boudet 7888 (ALF). Wabe Shebele Wenz, 1891/92, Keller 6 (GH, Z).

(FT).

BAKOOL:

Athroisma

boranense Cufod. (Figure 2 7)

Cufodontis (1943: 108). - PoZycZine haareri Dandy 256). - Type: Cufodontis 402, Borana: Javello, holotype; FT, W isotypes).

var. javellensis Lanza (1939: 1600 m, 16.iv.1937. (FT

Athroisma boranenre Cufod. var. hispidum Cufod. (1943: 109). - Type: Corradi 7867, Mega, 8-24 Settembre 1939 (ET lectotype, selected here; W duplicate). Illustration Lanza (1939: 257, fig. 82 [photo]). Autapomorphies not mentioned in description: anther thickenings radial; glandular hairs present on bracts subtending

endothecial capitula.

Erect, c. 30 to 75 cm high, perennial herbs with woody bases or subshrubs. Stems and branches densely pubescent and glandular, green, becoming grey or brown and almost glabrous. Rhizome present. I,EAVES not petiolate, pubescent, glandular, basally three-veined. Lowermost leaves often remaining when dry. Lamina entire, elliptic, narrowly ovate, or obovate (some basal leaves), c. 2-7.5 x 0.6-2.8 cm, kchartaceous; apex acute to acuminate, not apiculate; margin serrate or subentire, revolute, at least basally with l-l.5 mm long hairs; base attenuate; teeth thickened at apex but not apiculate. Petiole absent. Leaves reach (lo-)30-130 mm below (usually well below) the glomerule, gradually decreasing in size. S~xI~LORESC:ENC:ES dichasial or simple, of l-4(-6) glomerules; branches robust, pubescent. GLOMERULES 1 l-20 mm, containing c. 35-50 white to slightly pink capitula. C:.APITULA 2-3 mm wide, with female florets and c. lo-30 hermaphrodite florets. BR;K:TS elliptical to obovate -(median) or triangular (basal); apex acuminate; margins flat, ciliate, hyaline part narrow to wide; abaxial side glandular and pubescent; adaxial side glabrous. Median bracts 3-4 x 1.5-2 mm. Basal bracts 4-6 x 2-2.5 mm. II\'\'• LUCXALBRACTS narrowly obovate, 3-3.5 x 1.5-2 mm; apex obtuse; margin ciliate, widely hyaline; both sides glabrous or with a few hairs on abaxial side. IQI~I:~\E elliptic, 3.5-4 x 2 mm; apex obtuse, obscurely three-lobed; abaxial side glandular basally. C:OROLLA of female florets (1.5-)2 mm, slightly widened at apex, with few glands. COROLLA of hermaphrodite florets 2 x 1.5-2 mm; tube glandular. Anthers 1.1-1.3 mm; tails 0.2 mm. Style 2 mm. CYPSELAS obovate to elliptical in outline, not narrow near middle, l-l.5 x0.5-1 mm, with scattered hairs, eglandular or glandular; lateral ridges indistinct; surface smooth or slightly tuberculate with twin-hairs on tubercles; twin-hairs c. 0.1 mm, with diverging apical branches (some very short); pappoid corona absent; neck c. 0.1 mm. Receptacle 2-4 mm.

148

T. ERIKSSON

Figure 27. Athroima boraneme. A, flowering branch; B, basal subtending bract; subtending bract; D, involucral bract; E, female floret; F, palea; G, hermaphrodite twin hairs; I, anther (A, D Conadi 7867; B, C Sebsebe 7228; E, G Boudet 7679; 74255). Same scale as in Fig. 23.

C,

median floret; H, F, H Gillett

THE

GENUS

AZYZ-ROZSMA

149

Distribution and habitat Athroisma boranse has been found only in the mountainous southernmost part of Ethiopa (Sidamo region, Fig. 26) in grasslands, among rocks or in ‘waste land’; in open to closed vegetation (Juniperus forest; Acacia-Lannea bushland); on hillsides and in valleys. It is reported to grow on black clayey soil and red sandy soil at an altitude of c. 1400-1950 m. It has been collected in flower from April to December with the exception of August and October. Intermediates between A. boranense and A. gracile (see below) are found in three main areas (Fig. 28): (Al) In north-eastern and eastern Kenya, scattered or locally abundant in dry bush or woodland, more open grassland areas or subdesert, often near temporary water courses or mud-flats; on (yellow) sandy soil or shallow soil over limestone rocks. Reported to have been found with Acacia, Commiphora, Dobera, Grewia, Terminalia spinosa, Craibia brevicaudata and Strychnos. Flowering February, April to July, and November. Altitude 50-600 m. (A2) In the Nairobi-area in Kenya, found in ditches, in seasonally swampy grassland. The genera Eragrostis, Cyperus and Fimbristylti have been recorded from one collection site. Flowering April, June to September, and December. Altitude 1520-1750 m. (B) In two areas in Tanzania: The Serengeti plain and at Mt. Hanang. At the latter locality it is common among grasses in Acacia-Commiphora bushland on a reddish loam. Additional genera recorded: Themeda, Sporobolus Eragrostis, Thespesia, Dombeya, Lannea and Ximenia. Flowering February, March and July. Altitude 1370-1950 m.

Figure Unfilled Africa.

28. Known distribution of intermediates between A&hroisma graci& and 2. boranense. circles denote approximate localities. The map shows a section of the coast of East Cf. Fig. 26 for altitude scale.

1.50

T. ERIKSSON

Notes Athrozkma boranenre is recognized by the more or less elliptic sessile leaves which have three types of trichomes (Fig. 1): common uniseriate hairs, glandular hairs and gland dots. The hair covering is somewhat variable but hairs: usually dense. Three species share the character of having glandular A. borunense is distinguished from A. ha-#&urn by the leaves being elliptical without petiole rather than widely ovate and petiolate; and from A. pusillum by not being an annual and by having single or few glomerules placed apically well above the leaves rather than laterally. In A. boranense as well as in A. hastifolium the old basal leaves on a shoot usually remain when dry. The leaves vary in the amount of hairs, as mentioned above, and also in the amount of teeth. Most collections have distinct teeth, but a few are almost entire. Most collections are weakly branched rhizomatous herbaceous perennials, bearing mostly apical branches associated with the glomerules. A few collections however (Sebsebe 1228, Mooney 7317 and possibly Gillett 14255 and Frisk et al. 874) are more shrubby in aspect, some being branched from the base. I have not found any geographical or altitudinal pattern to this variation and no varieties are recognized here. The growth form and the amount of pubescence seem rather plastic. Vernacular name: Kunnieito (intermediate specimen from Marsabit dt. in Kenya).

Intermediate specimens In Kenya and Tanzania, south of the distribution area of A. boranense a number of specimens have been collected which I have interpreted as being results of introgressive hybridization with A. grucile (cf. species delimitation section). These collections have some characters from A. borunense and others from A. grucile as might be attributed to hybrids. Geographically they may be referred to as three ‘groups’, bearing in mind that these groups are not homogenous. In the intermediates, the characters displayed are a mix from the supposed parental species. None of the characters are present in all collections. In general, however, the intermediates look much like A. grucile with almost non pubescent but somewhat variable leaves usually with involute margins. The specimens of groups Al and A2 (except one) have female florets, gland dotted leaves, and subtending bracts like A. boranense and some of them have glandular hairs on the leaves. The specimens generally tend to be more like A. gracile the closer they are to the main distribution area of that species though this is not true for all specimens. The north-eastern group (A2) have group (Al) h ave rather wide leaves while the Nairobian long and narrow leaves. Agnew (1974: 448) proposed the latter as a candidate for species rank (Athrotima sp. A). They are quite similar, however, to the north-eastern group except for the slightly narrower leaves. The Tanzanian specimens from Mt. Hanang and Serengeti (group B) lack- female florets and are very similar to A. grucile in the leaves and the subtending bracts but they have gland dots (mainly on upper side of the leaves), similar hairs as those of some of group A, and old leaves are retained as in A. boranense.

THEGENUS ATHROISMA

1.51

Collections examined (7 6) ETHIOPIA, SIDAX~IO, BORENA: Filtu, 3.xi.1972, Boudet 7679 (ALF). 15 km SE of Negele, 18.vii.1962, Burger 7824 (FT, M). c. 16 km SE of Negele, along the rd to Filtu, 5”15’N 39”40’E, alt. c. 1400 m, 2.xi.1972, Friis, Gilbert, Rasmussen 6' Vollesen 874 (C, K). SID~WO, ARERO: 37 km S of Agere Maryam on new rd, 5”17’N 38”15’E, alt. 1615 m, ll.v.1976, Gilbert @Jefford 4385 16.iv.1937, Cufdontis 402 (l!T, W); 2 km on rd to Konso, (K). Yabelo, 4”54’N 38’6’E, alt. 1780 m, 12.v.1976, Gilbert @ Jej%rd 4476 (K). Mega, 824.ix.1939, Corradi 7867 (FT, W); Corradi 7885 (FT); 9.ix.1939, Corradi 7892 (F”T); 27.iv.1939, Corradi 2052 (FT, W); 2 km towards Addis Abeba on an hilly area, ah. 1850 m, 27.xii.1982, Sebsebe 7228 (ETH); 4”5’N 38”20’E, alt. 1950 m, 4.xi.1952, GiZZett 74255 (B, BR, EA, FT); by roadside in waste land, 4”5’N 38”22’E, alt. 1650 m, 8.vii.1958, Mooney 7377 (EA, ETH, K); 1 km N of Mega, 4’04’N 38”19’E, alt. c. 1900 m, 24.v.1986, Mesjin & fiZZesen 4270 (K); c. 4 km N of Mega, alt. 1920 m, 8.vi.1988, Gilbert &’ Sebsebe 8809 (K). 9 km on Magado-Mega track, 3”56’N 38”15’E, alt. 1525 m, 25.v.1986, Me@ & VoZZesen4324 (C, K, UPS). Intermediates between A. boranense and A. gracile collections examined (78) Northeastern group (AI). KENYA, NORTH EXXERIV, M..\NDER~\ D-r: 6 km S of El Wak, c. 2’46’N 40’56’E, alt. 420 m, 30.iv.1978, Gilbert @ 77zuZin 7234 (EA, K, UPS). D amassa Pan, margin, 3’9’N 41”19’E, alt. 375 m, 26.v.1952, GiZZet 73327 (B, BR, EA, FT, K, S, W). W)\JIR DT: Dadaab-Wajir rd, 38 km N of Sabule airstrip, O”40’N 40”7’E, alt. 190 m, 29.xi.1978, Brenan, GiZZet @ Kanuri 74877 (or 14841) (C, EA, UPS). E ..\s.r~I LRN, M~RS~WIT D-r: Dida Galgalu, in slight depression, c. 3”5’N 38”15’E, alt. c. 600 m, 13.ii.1953, GiZZett 75093 (EA, K). Logaloga (Lokuloko), vi. 1976, Sato 99 (EA). Co,\sr, TAI‘\‘..\ RIVER D-r: Garsen-Malindi rd, 23 km S of Garsen Hill, 2”31’S, ah. c. 50 m, 19.vii.1972, GiZZet &’ Kibuwa 79998 (EA, K). Nairobi group (‘2). KENYA, CENTRAL, Kr..\hruu DT: Thika, field between the Thika turnoff (at BP petrol station) and the Thika Gymkhana tennis courts, l”3’S 37”5’E, alt. 1520 m, l.vii.1971, Faden, Lye &’ Katende 77/534 (EA). Kiambu, ah. 1750 m, vi.1932, Mainwaring 2099 (EA). ~~~~~~~~ DT: Karura Forest, alt. 1675 m, l.vi.1941, K. F. Excursion 79 (EA). Muthaiga, alt. 1750 m, iv.1932, Mainwaring 7863 (EA). Near Nairobi, viii.1903, Wzyte s.n. (K). Nairobi, St. Michael’s rd, next to French mission, l.xii.1946, Rayner 238 (EA). Unidentified localities: Nairobi, viii.1903, AZZaud 37 (P). Kenya, ix.1916, Dowson 768 (EA). Hanang-Serengeti group (B). TANZANIA, ARUSHA, MONDULI: Serengeti Nat. Park, 6.vii.1973, Mwasumbi LBM 77772 (DSM); Serengeti plain, alt. 1371 m, 12.iii.1970, Richardr 25647 (EA, SRGH). HANAMG: Katesh-Nangwa, on the foot slopes of Mt. Hanang, alt. 1950 m, 4.ii.1946, Greenway 7567 (K). Road Singida-Babati near Mt. Hanang, escarpment hill side, alt. 1500 m, 30.iii.1965, Richards 20002 (K). Athrotima hastifolium Mattf. (Figures 2, 29) Mattfeld (1936: 298). - ,Type: Troll Muansa: Zwischen Oldeani und dem (B lectotype, selected here).

5605, Ost-Afrika (Tanganjika), Bezirk Manjara-See, 1700 m, 28 Iv&z 1934

152

T. ERIKSSON

Figure 29. Adroima hmtifolium A, flowering branch; B, basal subtending bract; C, median subtending bract; D, involucral bract; E, female floret; F, palea; G, hermaphrodite floret; H, twin hairs; I, anther; J, leaves (A Friti @ Hansen 2608; B, D, E, F, G, I, H Eriksson et al. 528; C, 53 Vaughan 3067; Jl V&ko;rt 3664; 52 G reenzuuy 9794. Same scale as in Fig. 23, scale of J = A. Cf. Fig. 2.

THE GENUS ATHROZSIW

153

Note. Mattfeld indicated a specimen in ‘Herb. Berol’. as type. That particular sheet, however, is not present there now and was probably destroyed in 1943, cf. Hiepko (1978). The specimen selected here as lectotype is a and labelled (P. duplicate which was saved at that time, recently mounted Hiepko in litt.). Autapomorphies not mentioned in description: leaves approximately as long as wide; bracts with long marginal cilia. Erect, c. 15 up to 60 cm high, perennial herbs with woody bases. Stems and branches densely pubescent, usually glandular, green to yellowish green, becoming brown and almost glabrous. Rhizome present. LEAVES petiolate, pubescent, glandular (densely on lower side), basally three-veined (palmate in one ~011.). Lowermost leaves remaining when dry. Lamina entire, triangular to ovate, c. 3-6.5 x 2-5 cm, chartaceous; apex acute to acuminate, not or basally with l-2 indistinctly apiculate; margin serrate, revolute, pubescent, mm long hairs; base truncate or almost hastate to attenuate; teeth thickened at apex but mostly not apiculate. Petiole lo-25 mm. Leaves reach 40-210 mm below the glomerule, of normal size. SYNFLORESCENCES dichasial or simple, of l-4(-6) glomerules; branches robust, pubescent. CLOMERULES 13-20 mm, containing c. 20-40 white to pinkish capitula. CAPITULA 2-3 mm wide, with female florets and lo-15 hermaphrodite florets. BRACTS lingulate to narrowly ovate to ovate; apex acuminate; margins flat, ciliate, hyaline part narrow; abaxial side slightly pubescent; adaxial side glabrous. Median bracts 3-5 x l1.5 mm. Basal bracts 4-5 x l-2 mm. IIWOLUCRAL BRACTS obovate to elliptic, 3-4 x 2 mm; apex obtuse; margin ciliate, widely hyaline; both sides glabrous or with a few hairs on abaxial side. PALEAE ovate, 4-5 x 2-3 mm; apex f truncate, obscurely three-lobed; abaxial side glandular basally. COROLLA of female florets 2-2.5 mm, widened at apex, glandular. COROLLA of hermaphrodite florets 2.5-3 x 1.5-2 mm; tube glandular. Anthers 1.3-1.8 mm; tails 0.2-0.4 mm. Style 2.5-3 mm. CYPSELAS ovate to elliptical in outline, not narrow near middle, l-l.5 x 1 mm, with few scattered hairs, eglandular; lateral ridges indistinct; surface tuberculate to rugose, often with twin-hairs on tubercles; twin-hairs
154

T. ERLKSSON

Figure 30. Known distribution of Athroivna hustijXum (0) and A. pudlum symbols denote approximate localities. The map shows a section of the coast and Lake Victoria. Cf. Fig. 26 for altitude scale.

(W). Unfilled of East Africa

Notes Athroisma hastifolium is recognized by the petiolate, entire, coarsely toothed, hairy leaves which usually are wide as long, and which are in most cases very glandular. The glomerules are usually distinctly above the leaves. In several characters, A. hastifolium is similar to A. boranenx it often bears old dry leaves at the base of the stems; presence of female florets; leaves which are (usually) densely glandular; presence of glandular hairs. It differs from A. boranense by having distinct petioles and by the leaves being approximately as wide as long. A notable feature is the surface of the cypsela, which may vary from tuberculate to rugose between specimens and also with the degree of maturity of the cypselas in that older cypselas are more rugose. In cases when the cypselas are only tuberculate, a twin-hair may be found on top of the tubercle, just as in some specimens of A. proteiforme, and A. pinnatzjidum. Rugose cypselas are also present, and show similar patterns of variation, in A. Facile ssp. psyllioides. A. hastifolium is sympatric with A. gracile with which it seems to introgress (cf: species delimitation section). A few of the specimens included here in A. hastifolium may be affected (infected) by features from A. gracile: Le$pert 5737, having narrow ‘leaves and short cypselas; Greenway 6779, almost lacking

155

THE GENUS ATHROISM4

leaf glands and having rather narrow leaves. As delimited here, specimens which more obviously seem affected by introgressive hybridization are found under A. gracile ssp. psyllioides. Such specimens have glabrous leaves, they lack female florets, and have more narrow leaves than A. hastifolium. Chromosome number 2n = 20 (Acquisition nr. SU-S-900709.12, seed from Eriksson et al. 528). Collections examined (35) KENYA, RIFT VALLEY, ILJIADO DT: Ngong Hills area, by Magadi rd near Masai settlement c. 2 km along road from Ngong Hills, 24.iii.1977, Kuchar @ Ma& 5777 (EA). Ngong Hills near Kekonyokie, alt. 1500-1800 m, lO.vi.1963, lrerdcourt 3664 (BR, EA, K). Mile 30 Magadi rd, alt. 1675 m, 30.i.1933, uan Someren 2468 (EA, F’I’, K). S of Kaijado-Namanga rd, 15.vi.1957, Greenway 9798 (EA, K, SRGH). Kajiado-Namanga rd, 18.v.1974, Kokwaro, Mathenge @ Mbuvi 3430 (EA, K). Mile 79 Nairobi-Namanga, 15.xii.1959, Verdcourt 2592 (BR, K). Oloitokitok, alt. 1525 m, 2.i.1960, McCarthy 9 (EA); 2.ii.1960, Rauh 276B (EA)F; Rauh Ke277 (EA). TANZANIA, KILMWJ..\RO, Hxr D-I-: Ngare Nairobi, 21.v.1953, Wallace 7326 (EA). W slopes of Kilimanjaro, Ngare Nairobi, in a shallow valley, alt. 1475 m, 5.vii.1943, Greenway 6779 (EA, K). San y a J uu, 3’8’s 37”2’E, alt. 1225 m, l.i.1967, Robertson 437 (EA, K); ah. 1500 m, l.i.1967, Richards 27876 (K). ARUSHA, ARUMRU DT: By road from Ngare Nanyuki to Nairobi-Arusha main rd, ah. 1525 m, 2.i.1971, Richards &‘ArasuZuZu 26450 (K, SRGH); 10 km W of Ngare Nanyuki, 3”9’S 36’50’E, alt. 1600 m, 27.iv.1975, Friis &’ Hansen 2608 (C, EA, K); 11 km W of Ngare Nanyuki, c. 3”08’S 36”48’E, alt. 1450 m, 9.vi.1990, Eriksson, Kalema & LeZiyo 528 (NHT, S, TEX); alt. 1219 m, 26.xii.1968, Richards 23474 (EA, K); Mkuru-Ngare Nanyuki, ah. 1615 m, 21.xii.1969, Richards 24979 (K). M eru E, near top of ash cone, ah. 3350 m, 2 1.i. 1938, Cooper 86 (BM). Karangai-Arusha, alt. 925 m, 1l.v. 1963, Green 7697 (EA, NHT). L ower Nduruma, alt. c. 975 m, vi.1928, Haarer 7420 (EA, K). MONILILI DT: Monduli, v.1938, Rowe 7 (EA); Ardai dip area, 7.ii.1968, Musomi 77 (EA). Ardai plains, 5.vi.1944, Fuggles-Bauchman 57 (EA). Eluanata, 60 km from Arusha on Dodoma rd, ah. c. 1350 m, 10.v.1965, Leippert 5737 (EA, K). Arusha-Babati rd, 22.iv.1940, Vaughan 3067 (BM, EA). 3 miles NE of Makuyuni, alt. 1125 m, 17.v.1963, Welch 526 (EA, K). Ngorongoro, Newbould 6529 (EA); 16.ii.1959, Hendy 7556 (EA); 15.v.1981, Chuwa 2079K (DSM). MBULU DT: Lake Manyara, first rift wall terrace, ah. c. 975 m, 11 .v. 196 1, Karani s.n. (K). Lake Manyara Nat. Park, S of Msasa River, ah. 1375 m, 11 .xii. 1963, Greenway @? Kirrika 7 7 7 73 (EA, K). Upper part of the escarpment beside the Mto Wa Mbu-Karatu rd, c. 3”22’S 35”50’E, ah. 1150 m, 1 l.vi.1990, Eriksson, Kalema &? Leliyo 535 (NHT, S). Between Cldeani and Lake Manyara, alt. 1700 m, 28.iii.1934, Troll 5605 (B). Mbulumbul, alt. 1925 m, 26.vi.1945, Greenway 7476 (EA, K).

Athrozbna psilocarpum T. Eriksson

sp. nov.

(Figure 3 7) Type: Humbert 72525, Plantes de Madagascar du Mandrare pres d’anadabolava, Decembre

(4e voyage), Vallee moyenne 1933 (P holotype; P isotypes).

156

T. ITXUKSSON

Figure 31. Afhtoisma psilocarpum sp. tlov. A, flowering branch; B, basal subtending bract; C, median subtending bract; F, palea; G, hermaphrodite floret; I, anther; (A-I Humberl 12525). Same scale as in Fig. 23.

THE GENUS

157

ATHROISWI

Illustration. Humbert (1962: 582, fig. 59 [7]). Note: The epithet refers to the entirely glabrous cypselas of this species. young capitula with not mentioned in description: Autapomorphies conspicuously protruding leaf-like recurved subtending bracts; paleae with visible venation (resin ducts). Diagnosis. subtentis,

bracteis A speciebus aliis capitulis et cypselis omnino glabris differt.

grandibus

spice

recurvatis

Erect more than 20 cm high, perennial herbs, somewhat woody at base. Stems and branches pubescent, green, becoming glabrous and light brown. Rhizome unknown. LEAVES petiolate, pubescent (mainly on lower side), glandular on lower side, penninerved with one vein basally. Lowermost leaves not remaining when dry. Lamina shallowly incised, eliptic, c. 5.57.5 x c. 2.5-3.5 cm, chartaceous; apex acute, apiculate; margin f deeply serrate; margin slightly revolute, with scattered hairs; base attenuate; teeth apiculate. Petiole 15-25 mm. leaves reach lo-15 mm below the glomerule, of normal size. SYNFLORESCENCES dichasial, of l-3 glomerules; branches slender, pubescent. GLOMERULES c. 10 mm, containing 20-25 (probably greenish white) capitula. CAPITUW width not known, without female florets, with 8-l 1 hermaphrodite florets. BRt\crs ovate to elliptic; apex acuminate; margins flat to apically involute, ciliate, hyaline part absent or indistinct; abaxial side pubescent and glandular; adaxial side glabrous. Median bracts 3.5-5 x 1.5-2 mm. Basal bracts 5-6 x 2-3 mm. INVOLUCRAL BRACTS absent. PALEAE f elliptical, 3.5-4 x 22.5 mm; apex obtuse, with 2-4 narrow lobes; abaxial side glabrous or with a few hairs. COROLLA of hermaphrodite florets 2.5 x 1.5 mm; tube glandular. Anthers 1.2-1.5 mm; tails 0.1-0.2 mm. Style 2.5 mm. CYPSELAS obovate to slightly obcordate in outline, not narrow near middle, 1.5 x0.5-1 mm, glabrous, eglandular; lateral ridges f distinct; surface smooth; pappoid corona absent; neck 0.1-0.2 mm. Length of receptable not known. Distribution and habitat Athroisma psilocarpum has been found only once, south of the mountains in south-eastern Madagascar (Fig. 32). It was collected in a riverine valley dry forest at an altitude of 200-250 m. Notes The only available material is unfortunately young,’ but is nevertheless easily distinguished on its glabrous cypselas, and the large leaf-like subtending bracts. The leaves are deeply serrate towards being incised with blunt teeth looking somewhat like some specimens of A. lobatum. In this species, however, the leaves are penninerved. Humbert (1962, fide ~011.) considered this species to be a form of Athrokma (as Polycline) proteiforme. No collections

except

type.

Athroisma pusillum T. Eriksson (&we

sp. nov.

33)

Type: Drummond &’ Hemsely 4073, Kenya, Kwale district, Between Samburu and Mackinnon Road, 3 1.8.1953 (K holotype; B, BR, EA, FT, K isotypes).

T. ERIKSSON

158

0

Figure 32. Known distribution proleifonc (m). Unfilled symbols

Note. The specific epithet

100

200km

of Alhrotima psilocarpum (A), denote approximate localities.

refers to the small

A. pinnatifidum (@), and A. The map shows Madagascar.

glomerules.

Diagnosis. A speciebus aliis foliis angustis basaliter et glomerulus ut videtur lateralibus differt.

cordatis

nervatura

palmata,

Erect 25 to over 45 cm high, annual herbs. Stems and branches almost glabrous, green, becoming yellowish green and basally pinkish. Rhizome absent. LEA\W petiolate, not pubescent, glandular (mainly on lower side), basally palmately veined with one main vein (three-veined in a few leaves). Lowermost leaves not remaining when dry. Lamina entire, narrowly triangular, c. 3-6 x c. 0.8-1.5 cm, chartaceous; apex acuminate, slightly apiculate margin serrate to dentate mainly towards base, slightly revolute, with scattered hairs, basally with l-l.5 mm long hairs; base shallowly cordate; teeth not apiculate. Petiole lo-20 mm. Leaves reach 25-45 mm below the glomerule, of normal size. SI’NFLORESCENC:ES monochasial, with seemingly lateral glomerules, of c. 5-10 glomerules; branches slender, glabrous. GLOW:RULES 5-9 mm, containing 35-45 white to pink capitula. CNWUW 2 mm wide, without female florets, with g-12(-15) hermaphrodite florets. IXK:TS obovate; apex acute to acuminate; margins flat, ciliate, hyaline part wide; both sides glabrous. Median bracts 2-2.5 x l-l.5 mm. Basal bracts 2-2.5 x 1.5 mm. IWOLUC:RAL BRACTS absent. IJALEAE obovate, 2 x l-l .5 mm; apex + truncate, obscurely three-lobed; abaxial side glandular basally, glabrous or with a few hairs. COROLLA of hermaphrodite florets 1.5 x 1 mm; tube glandular. Anthers 0.8-0.9 mm; tails 0.1 mm. Style

THE

GENUS

ATHROISMA

F2

Figure 33. Athrobnuz median subtending twin hair; I, anther as in Fig. 23.

159

G

H

@.riUum sp. nav. A, flowering branch; B, basal subtending bract; Fl, basal palea, F2, median palea; G, hermaphrodite (A Faden t3 Faden 721720, B-I Drummond t3 Hem&y 4073).

bract; C, floret; H, Same scale

1.5 mm. C:YPSEIAS elliptical in outline, not narrow near middle, 1 x 0.5 mm, with scattered hairs, glandular; lateral ridges indistinct; surface smooth; twinhairs 0.1-0.2 mm, with recurved apical branches; pappoid corona absent; neck c. 0.1 mm. Receptacle c. 2 mm long.

”

161

THE GENUS ATHROISMA

Notes Athroisma pusillum is recognized by its small glomerules placed seemingly laterally along the otherwise straight stem. The synflorescences are monochasial but at each branching point the (usually) single branch becomes the main stem. Also, the leaves are special in their narrowly triangular form. This species have small glandular hairs on the leaves, a character which it shares with A. boranense and A. hastifolium. Collections examined KENYA, COAST, KWALE D-r; Between Samburu c. 350 m, 31.viii.1953, Drummond & Hemsley 4073 DT; Tsavo Nat. Park East, Ndara to Dida Harea, 3, 3”25’S, 38’44’E, alt. c. 500 m, 29.i.1972, Faden

and Mackinnon Road, alt. (B, BR, EA, FT, K). TAITA sign post 141 to 139, km @ Faden 721720 (EA, K).

Athroisma pinnatz$dum T. Eriksson

sp. nov.

(Figure 34) Type. Humbert 6’ Perrier de la Ezthie 2507, Delta du Fiherenana, 14-26 Sep. 1924 (P holotype; G, K, P isotypes). Illustrations. Humbert 5d [pollen]). Note. The

specific

(1962: epithet

582, fig. 59 [4-6,

refers to the pinnatifid

11, 16-171);

Skvarla

alt. l-20

m,

(1977: Pl.

leaves of this species.

Diaposis. A Athroismate proteiformi foliis anguste coronis pappoidibus non squamiformibus differt.

et ordinate

lobatis,

et

Erect up to 2 m high, perennial sub-shrubs or shrubs. Stems and branches glabrous or with few scattered hairs and glands, green, becoming brown to reddish brown and glabrous. Rhizome unknown. LEAVES petiolate, pubescent on upper side only (especially on midvein), glandular (some eglandular on lower side), basally three-veined. Lowermost leaves not remaining when dry. c. 4Lamina pinnatifid, with many lobes, ovate to obovate in outline, 11 x 2.5-7.5 cm, chartaceous to somewhat coriaceous; apex acuminate, apiculate; margin entire, involute, glabrous; base ‘truncate’; lobes 3-7 lateral, fsubopposite, linear, lateral ones l-3 (4) mm wide, apical one l-3 (5) mm wide. Petiole 5-32 mm. Leaves reach 4-25 (-70) mm below the glomerule, gradually decreasing in size. SYNFLORESCENCES dichasial, often with clustered glomerules, of 2-8 glomerules; branches slender, glabrous. GLOMERULES lo25 mm, containing 8-25 white to creamy green capitula. CAPITULA 3-5 mm wide, without female florets, with 8-18 hermaphrodite florets. BRACTS ovate; apex acuminate; margins involute apically, ciliate, hyaline part absent; both sides&pubescent and glandular. Median bracts 4-5 x 2-2.5 m,m. Basal bracts. 4-5 x 2-2.5 mm. IM~OLUCXAL BRA~TS absent. PALEAE ovate, 4-5.5 x 2.5-3 mm; apex+ truncate, with c. three narrow lobes; abaxial side glabrous or with a few hairs. COROLLA of hermaphrodite florets 3-3.5 x 2-2.5 mm; tube glandular. Anthers 1.9-2.2 mm; tails’ 0.2-0.3 mm. Style 3-3.5 mm. CWSEIAS obovate in outline, not narrow near middle, 2-2.5 x l-l.5 mm, with marginal and scattered hairs, eglandular; lateral ridges distinct; surface smooth; twin-hairs

lG2

T. ERIKSSON

0.2-0.3 mm, with ascending apical branches; pappoid corona of two lateral narrow filiform projections or almost absent; neck 0.1-0.2 mm. Receptacle 3-6 mm. Distribution and habitat Athroisma pinnatz$dum is distributed rather close western Madagascar’ (Fig. 32). It is found on sandy limestone in dry forest, dry scrub, spiny desert, and been reported to be common or occasional, growing Euphorbia, Croton, Terminalia, Grewia, Commiphora, Altitude l-500 m.

to the coast in southor rocky ground with on coastal cliffs. It has together with AZZaudia, Sarcostemma and Cissus.

Notes ‘It is distinguished from all other species on its narrowly pinnatifid leaves with many (usually 4-6) lobes. In some cases it is similar to A. proteifrme but differs by lacking the scale-like pappoid corona of that species, and by regularly having, as the only species in the genus, twin-hairs which are Tshaped or Y-shaped. The petiole is in this case measured as the distance from the leaf base up to the basal lobes. In the original description and the specimens of this species in P. later, Humbert (1962; 1923) included proteiformis. Vernacular name: Manjakatety. Collections examined (42) Toliara, xi.-i. 1868-69, Grandidier s.n. (P); MADAGASCAR, TOLIAILX 12.xii.1912, AfzeZius s.n. (S, UPS). Fiherenana valley, ix.1905, D’AZZeizette s.n. (L); 12.iii.1960, K eraudren 659 (P), Andranovory, 19.viii.1960, Peltier &’ Peltier 2523 (BR, P). Delta of Fiherenana, ah.. l-20 m, 14-26.ix.1924, Humbert & Perrier 2507 (G, K, P); alt. l-10 m, 6.viii.1928, Humbert & SwingZe 5777 (B, BM, C, G, K, P, S). Onilahy estuary, at St. Agustin, alt. l-20 m, 2123.i.1947, Humbert 79967 (G, P); 8.i.1957, Descoings 2472 (K). 8-16 km E of Toliara on rd to Antananarivo, alt. c. 50 m, 7.ii.1975, Croat 30990 (P). Vicinity of Toliara Table Mtn, 1952-55, Dequaire 27.352 (P); 9.iii.1960, Keraudren 567 (P); 29.iii.1921, Poisson 767 (P); 23”2O’S, 43’40’E, ah. c. 20 m, 14.iv.1971, Mabberley 936 (EA, K); Mabberley 937 (EA, K). Limestone plateau of Toliara, v.1910, Perrier 3340 (K, P). Mahafaly limestone plateau, 16.x.1970, Keraudren-Aymonin @ Aymonin 24752 his (P). Mahafaly coast between Onilahy and Anakao, 2O.iii.1955, Humbert 29570 (P). Onilahy valley near Tongobory, ah. 50-200 m, 5.ii.1947, Humbert 20756 bis (P). Between Tongobory and Betioky, viii.1919, Perrier ? s.n., (P). Along the road to Antanimena at Betioky, 8.iv. 1922, Poisson 408 (P). Lake Tsimanampetsotsa, 15-l 7.iv. 196 1, Peltier &? Montagnae 3742 (P). Reserve Naturelle 10, Riserves Nat. ~RaveZonanahavy) 2782 (P). W of Ejeda, 15.v.1951, Bosser 269 (P). Efoetsy, 12.v.1951, Bosser 790 (P). Sandy ground N of Itampolo, alt. l-10 m, 17-24.viii.1928, Humbert @ Swingle 5358 bis (P). Itampolo, 2O.vi.1929, white s.n. (BM). Ampanihy, 3.viii.1971, Huine 28a (K). Ranopiso, 29.vii.1932, Decary 70.788 (P); Tsimelahy, 9.viii.1950, Rhserves Nat. (Ramarakotu) 27 72 (P). Andrahomana, 18.vi.1926, Decary 4064 (P). Near Bevilany, ah. 200-30 m, 14.ix.1928, Humbert @ SwingZe 5709 (P).

lb3

THEGENUS ATHROISMA

Eastern edge of parcel 2 of Reserve #1 1 (Andohahela) near Ambatombo, a village at the end of road 51 km NE of Ambosary, 24”5O’S, 46’40’E, 18.iii.1987, Schatz 7275 (P). Between Behara and Tranomaro, 8.vi.1932, Decary 6.iv.1924, Decq 2607 (P); 7.ix.1931, Decay 9778 9894 (L, P). A m b ovombe, (P). Angavo Mts E of Antanimora, 20.vii.1926, Decury 4538 (P). Vicinity of Antanimora, alt. 200-500 m, 6-9.ii.1955, Humbert & Capruon 28836 (P). Vicinity of Tanjona Vohimena (Cape Sainte Marie), alt. 150 m, 5-7.iii.1955, localities: Madagascar, Humbert & Capruon 29240 (P). I nexact or unknown Cours 4555 (P). Tdlanaro (Fort Dauphin), 16.vi.1926, Decay 4770 (P). Athroisma

proteiforme (Humbert) (Figure 35)

Mattf.

Mattfeld (1936: 302). -PoZycZine proteiformis Humbert (1923: 103, 298). -Type: Mouroundava, C a f en juillet (P lectotype, selected Grevi 4, Madagascar, here; P duplicate). Illustration. Humbert (1962: 582, fig. 59 [l-3, Flora reference. Humbert (1962).

8-10,

181).

Erect c. 30-70 cm high, perennial herbs, somewhat woody at base. Stems and branches glabrous, green, becoming brown. Rhizome unknown. LE.A\~ petiolate (indistinctly in linear leaves), not pubescent (midvein on upper side pubescent in young leaves), eglandular (or glandular on lower side in young Lowermost leaves not remaining when dry. leaves), basally three-veined. Lamina entire or with a few lobes towards base, ovate to elliptic or linear in outline, c. 4-8 x 0.1-4 cm, + coriaceous; apex acuminate, apiculate; margin entire, some with a few teeth, flat to involute, glabrous; base attenuate; lobes when present l-3, +subopposite, narrowly obovate, lateral ones l-3 mm wide, apical one l-10 mm wide. Petiole indistinct or c. lo-20 mm. Leaves reach 4-30 mm below the glomerule, gradually decreasing in size. SI~~LORIISCE~~S + monochasial, of l-3 glomerules; branches slender to robust, glabrous. GI,O~KULI‘:S 12-22 mm, containing 15-20 creamy yellow (?) capitula. C:AWI~UI.~\ 3-5 mm wide, without female florets, with 14-23 hermaphrodite florets. BR;K:TS ovate (median) to lingulate (basal); apex acute to acuminate; margins slightly involute apically, entire to ciliate, hyaline part absent or indistinct; abaxial side glabrous; adaxial side pubescent, especially near margin. Median bracts 3-4 x 1.5-2.5 mm. basal bract’s 3-4.5 x 2-2.5 mm. I~'\'oLuc:R.~~I~UR.~K:n absent. PALEAE ovate, 4-4.5 x 3.5-4 mm; apex f truncate, with 2-3 unequal indistinct lobes; abaxial side glabrous or with a few hairs. COROLLA of hermaphrodite florets 2-3 x 1.5-2 mm; tube glandular. Anthers 1.3-1.6 mm; tails 0.1-0.2 mm. Style 2.5-3 mm. CWSEWS obovate in outline, not narrow near middle, 1.5-2 x 1 mm, with marginal and a few scattered hairs, eglandular; lateral ridges distinct; surface smooth or slightly tuberculate; twin-hairs c. 0.2 mm long, with& revolute apical branches; pappoid corona like short scales; neck 0.1-0.2 mm. Receptacle 3-7 mm. Distribution and habitat Athroisma proteijkme is distributed along c, 200 km of the western coast of Madagascar (Fig. 32). It has been collected alongside other genera as

T. EFUKSSON

Figure 3.5. Afhroisma proleifrme. A, flowering branch; B, basal subtending bract; C, median subtending bract; F, palea; G, hermaphrodite floret; H, twin hair; I, anther; J, leaves (A, B, F, G, I, J3 Grevi 4; C, H Rauh M863/59, Jl, J2 Mabbdey 750. Same scale as in Fig. 23, .scale ofJ=A.

165

THE GENUS ATHROISMI

Euphorbia, Pandanus, and Lomatophyllum etc. in forest or in clearings in forest at an altitude of up to 50 m. Collected in flower in March and in June to October. It is reported to be common. Notes Athroisma proteiforme is similar to A. pinnat$dum but the leaves are entire or almost entire with a few short lobes. Specimens with linear, unlobed leaves look much like. A. gracile from the African mainland, but A. protezjorme always has a well developed scale-like pappoid corona unlike those of A. gracile and A. pinnatzjidum. The petiole is in this case measured as the distance from the leaf base up to the basal lobes (if any). all specimens here placed in three Humbert (1962; 1923) considered species: A. proteiforme, A. psilocar-urn and A. pinnatiJidum, to belong to A. proteiforme. Collections examined (8) MADAGASCAR, TOLIARA: Ankirisa forest, near Beroboka, MorondavaBelo-Tsiribihina rd, 19”55’S 44’35’E, alt. c. 30 m, 20.iii.1971, Mabberley 750 (EA, K). Morondava, iii.1869, Grandidier s.n. (P); vii, Grevb 4 (P). Sandy plateau towards the upper basin of the Maharivo between Morandava and Tsiribihina, viii.191 1, Perrier 2757 (P). Belo-sur-mer, alt. 50 m, 20.x.1959, Rauh M863/59 (M). Morombe, by the sea, 1952-55, Dequaire 27.470 (P). Nosy Trozona near Morombe, 7.vi.1921, Perrier 73875 (K, P). Sandy ground between the Mangoky and the Manombo, ix.1919, Perrier 72854 (K, P). Collection of uncertain affinity: Maharoake, Andranolo, vii.1891, Douliot s.n. (0 Athroisma

gracile (Oliv.) (Figure 36)

Mattf.

Mattfeld (1936: 302). -Sph aeranthus gracilis Oliv. (1885: 400) gracilis (Oliv.) Oliv. (1894 t. 2293). -Type: Thompson s.n., Masai Kapte plateau, 9/1894 (K holotype).

-Polycline Country,

Erect, 10 cm to c. 1 m high, perennial herbs with woody bases. Stems and branches-glabrous, green, becoming brownish. Rhizome present. L-EA\'ES not petiolate or shortly petiolate, glabrous, basally one or three-veined. Lowermost leaves not remaining when dry. Lamina entire, linear to elliptic or obovate, c. 2-12 x < 0.1-2.5 cm, chartaceous to coriaceous; apex acute to acuminate, not apiculate; margin entire, dentate or serrate, involute to slightly revolute; base attenuate; teeth not apiculate. Petiole absent or up to 3 mm. Leaves reach c. 5-75 mm below the glomerule, gradually decreasing in size. SYSI:1.oRESC:I:SCES dichasial, of l-5(-7) glomerules; branches slender to robust, glabrous. C;I.OMERUI,ES 9-16 mm, containing c. 20-50 white to pink or purple capitula. C:.VITUL;~ 2-4 mm wide, without female florets, with 8-22 hermaphrodite florets. ISRXTS ovate to lingulate (basal) or obovate (median); apex acute to acuminate; margins apically involute or flat, ciliate or entire, hyaline part wide to almost absent; both sides glabrous or slightly pubescent abaxially. Median bracts 3-4 x 1.5-2 mm. Basal bracts 3-5 x 1.5-3 mm.

T. ERIKSSON

166

Figure 3(i. branch of palea; G, A2 Erikmn J3 Haarer

flowering branch of A. grade ssp. gracile; Al, flowering Alhroi’ma gracile. Al, A. gracile ssp. ,!qllioides. B, basal subtending bract; C, median subtending bract; F, hermaphrodite lloret; H, twin hairs; I, anther; J, leaves (Al, G, H Eri!mon 673, el al. 559; B, C, F, I Creenway B Kanuri 73792; JI Peter 40676; J’L Bally 73774; 582). Same scale as in Fig. 23, scale or J = A.

131~~:~s absent. P.W.I:AE obovate or ovate to rectanguloid, 2.54 x l-2.5 mm; apex f truncate, unlobed, slightly erose; abaxial side glabrous, ciliate or with a few glands. C:OIWIL\ of hermaphrodite florets (1.5-)22.5 x 1.5-2 mm; tube glandular. Anthers l-l.5 mm; tails 0.1-0.2 mm. Style 2-3 mm. C:YPSEL\S obovoidal or ellipsoidal to outline almost circular, not distinctly narrow near middle, l-l.5 x 0.5-l mm, with scattered hairs mostly near apex and base, glandular apically and basally; lateral margins indistinct; surface smooth to rugose; twin-hairs c. 0.1-0.2 mm long, with recurved apical branches to short straight branches (near middle of cypsela); pappoid corona absent, as short lobes, or as a ring of hairs; neck c. 0.1 mm. Receptacle 25 mm.

IS\Y~I.L‘C:RAI.

Distribution and habitat Athroisma gracile is distributed from northern Kenya to (Fig. 37). The distribution area connects in the north to forming an extensive zone of specimens of hybrid delimitation section and note, under A. boranense). In

northern Tanzania that of A. boranense origin (cf. species the southwest the

THE

Figure 37. Known distribution symbols denote approximate and Lake Victoria. Cf. Fig.

GENUS

167

AZ-HROlSMA

of Athroisma gracile. ssp. grackle (0); localities. The map shows a section 26 for altitude scale.

ssp. psyllioides (W). Unfilled of the coast of East Africa

distribution area connects to that of A. stuhlmanii but there is no indication of hybridization there (cf. species delimitation section). A. grade is sympatric with A. hastifolium, in an area approximately from Nairobi in Kenya in the north to the Kilimanjaro area in the south, with which it appears to introgress (cf. species delimitation section). Rare or occasional to very common, but local, in wet or dry open or more closed grasslands (savanna), woodlands or shrublands; on (grazed) roadsides and forest edges; swampy ground, ditches etc., or as weeds in cultivated grass. It is found on sandy, volcanic, and clayey soils of red, orange, grey or black colour (black cotton soil); or rocky stony ground; sometimes on very shallow soil. A. gracile has been collected during all year with about half of the specimens in June to August, and rarely collected in October to December and, in April to May. Notes According to the Masai (fide toll.) A. gracile is favoured and browsed by stock and game animals.. This, however, is not very likely since I have observed several cases in which A. Facile remained virtually untouched in otherwise overgrazed areas.

T. ERIKSSON

lGf.3

Athroisma

gracile (Oliv.) Mattf. . (Figure 36A)

ssp. gracile

Height c. 10 to 40 cm. L.EA\‘ES not petiolate with one or three veins basally. Lamina linear to narrowly elliptic or narrowly obovate, c. 2-7.5 x 0.1-0.5 cm; Petiole absent. RRAWS margin entire or with very few teeth, involute. subtending capitula ovate (basal) to obovate (median), entire; margins apically involute, slightly ciliate (median) or dentate (basal), hyaline part narrow or absent. Basal bracts 3-4 x 1.5-2 mm. Paleae 2.5-3.5 x l-2 mm; abaxial side glabrous or with a few small hairs. Anthers l-l.3 mm. Style 2 mm. C:~I’SI:L;\S l-l.5 x 0.5 elliptic to almost circular in outline, not narrow near middle, mm, surface smooth; pappoid corona absent, lobed, or as a ring of hairs. Receptacle 2-3 mm. Distribution and habitat Athroisma gracile ssp. gracile is confined to the north-western part of the distribution area (Fig. 37), i.e. the area which I interpret as unaffected by introgression with A. hastifolium. Altitudes from 1240-2400 m have been noted. It has been collected among the grasses Bothriochloa, Cymbopogon, Cynodon, Digitaria, Eragrostis, Eustachyus, Harpachne, Hyparrhenia, Loudetia, Pennisetum, Sporolobus and Themeda; alongside herbaceous genera including Becium, Berkeyopsis, Cyperus, Gutenbergia, Helitropium, Indigofera, Justicia, Oldenlandia, Pentanisia, Rhynchosia and Solarium; among trees and shrubs e.g. Acacia, Brachylaena, Euphorbia and Tarchonanthus. Notes Athrozsma gracile ssp. gracile differ from ssp. psyllioides in having completely smooth cypselas and usually narrower leaves which rarely have any teeth. Vernacular names: Oleitorot or Oleturot (Masai); Origibele-lengima (probably Masai, cf. A. grucile ssp. psyllioides); Ingigi (Kiumbulu). Chromosome number 2n = 20 (Acquisition nr. SU-S-900709.19, seed from Eriksson 673). Collections examined (59) KENYA, E.WTRS, M..\asl\srr D-r: Marsabit, vii. 1942, Bally 7855 (G). MI:RU DT: N Mt. Kenya, Ndare forest, alt. 1675 m, vii.1934, Porter 3233 (EA, K). MACHAKOS D-r: Yatta plateau, 4 km E of Athi R. on Machakos-Kitui rd, 1’25’S 37”41’E, alt. c. 1240 m, 27.xi.1982, Gillett, Mutangah tY Rucina 23950 (EA, K). Athi River, van Laethem 7 (EA). c. 3.5 miles N of Nunguni on the W side of mountain slopes in Kilhembe village, alt. c. 1890 m, 6.v.1968, Mwangangi 825 (EA, K). CEN-I-RAL, KIAMBL DX Kikuyu, 26.i.1903, Thomas IX.26 (P); 1903-04, Allaud s.n. (P). Kikuyu escarpment forest (Lari forest reserve and adjacent areas), l”OO’S-1”05’S, 36’35’E-36’38’E, ah. 1830-2130 m, 17.xii.1972, Hansen 877 (BR, C, EA, K). N airobi-Naivasha rd, picnic site viewpoint on Kedong escarpment, 1”02’S, 36”37’E alt. 2000 m, 15.vi.1977, Gilbert 4778 (EA, K, UPS). T op of Kedong escarpment, ah. 2125 m, viii. 1932,

THE

GENUS

ATHROISMA

169

Gardner 2896 (BM, BR, EA, K). Ndeya, 29.vi.1935, van Someren 8480 (EA, K). N..UROUI DY: Nairobi, S.viii. 1934, GoZdFchmidt s.n. (BM); 2.i. 1932, FitGibbon 1636 (EA, K); 22.i.1960, Rauh Ke97 (EA). Nairobi academy, Langata, ah. 1800 m, vi.1977, Timberlake 7249 (EA); alt. 1660 m, ii.1915 Dimmer 7965 (BM, K); Nairobi Dam, 25.vii.1950, Nathers 569 (EA); New race course, ah. 1825 m, 7.iv.1930, Napier 235 (EA, K). RIFI. Vr\~,~,~:y, B..IRISGO D-r: Kamasia Native Reserve, alt. 1675 m, x.1929, Lyne Watt 7325 (EA, K). UASIN G~SHU D-r: c. 40 km from Eldoret on Nairobi rd, ah. 2400 m, 9.ix.1968, Bonnejille 392 (EA). NAKL:IIC. DY: Near Eburru, alt. c. 2000 m, 1929, Humbert 9034 (P). Ilkek on roadside, ah. 1975 m, v.1968, Tweedie 3547 (K). Kijabe-Narok road, alt. 1700 m, 18.vi.1960, Greenway 9692 (EA). Narok rd, between Mt Margaret and Longonot Satellite Station, c. lo0 1’S, 36”32’E, 2.vii. 1990, Eriksson 673 (EA, S, TEX); Eriksson 674 (EA, S). Kedong valley, 60 miles NW of Nairobi, 18.vi.1926, Chapin 77 (BR). Mt Margaret estate, Kedong, alt. 1925 m, vi.1940, BaZZy 997 (G). Mt Margaret hill, Kedong Valley, alt. 1900 m, vi.1940, Bally 992 (G). 01 L on g onot estate, lO.v.1960, Kerfoot 7837 (EA, K). Old rd NairobiNaviasha, at the base of the escarpment before Mai Maihu, c. l”Ol’S, 36”36’E, 2.vii.1990, Erikrson 672 (EA, S). Kikuyu and on the road to Eldama ravine, 1898, W%yte s.n. (K). Kikuyu escarpment, viii, Sacleux 39 (P). N>\ROK Dr: Mt Suswa, steamjet ridge near Stafford camp, alt. 1825 m, l.i.1963, Glover, Wateridge, Donet @ Suribei PEG 3433 (EA). Noolpopong, UTM 37MAJ7172, ah. 1900 m, 8.viii.1977, Kuchar @Msajiri 6787 (EA). Langena Camp 10 miles from Narok on the Nairobi rd, on the left if facing Nairobi. Top of Seyabei Gorge, alt. 1675 m, 15.vii.1962, Glover & Samuel 3775 (BR, EA, K). Narok, in open places among Leleshwa, vii. 1957, ~011. ignot. 996 (NHT). Narok, Ndara quarantine area, alt. 1900 m, 24.vii.1957, Trapnell 2343 (EA, K). Narok, vii.1957, Iwem? s.n. (EA). Narok-Mara river, mile 15-20, 16.vi.1956, nerdcourt 7504 (EA, K). Eastern Loita Plains, c. l”25’S 35”50’E, 9.ix.1965, Kn&ht Ei473372 (EA). I n roadside ditches 40 km from Narok on rd to Masai Mara, alt. 1695 m, 29.iii.1977, Hoofer &Z’ Townsend 7573 (K, SRGH). Loita Plains, 25 km SW of Narok, along the rd to Keekorok, ah. 2000 m, 31.i. 1978, Boulos 72387 (M). K,~JI;\I,o D-r: Mt. Suswa on the northern part of the caldera, ah. c. 1825 m, 23.iii.1963, Glover & Balky 3533A (EA, K); Lower slopes on the N side, around old Masai bomas, ah. c. 1675 m, 9.x.1962, Glover & Samuel 3330 (EA, K). Ngong-Suswa km 30, Kedong Valley, alt. 1550 m, 31.i.1979, Bamps 6396 (BR, EA). Ngong, ah. 1825 m, 2F.iii.1941, Edwards 298 (EA). Kaputei Plains (Kapte plateau), ix.1894, Thompson s.n. (K). 30 miles Magadi rd, van Someren 70770 (EA). TANZANIA, ARUSH.-\, MOSI)L’I.I D-r: Olbaata, Olbalbal depression, in open grass plains, ah. 1375 m, 7.ii.1962, Newbould 5992 (EA). H!\s.-~\c D-I.: Kitingi, alt. 1700 m, l.iii.1965, Hukui 22 (EA, K). Manda, alt. 1500 m, G.iii.1965, Hukui 42 (EA, K). M,I\RA, SI:RISSGI:.I.I D-r: Serengeti Nat. Park, Banagi, 2”18’S 34’50’E, alt. 1350 m, 3.iii.1965, Leippert 5604 (EA, FYI); Seronera, alt. 1525 m, 24.i.1968, Ludanga R52 (EA); Simba k opjes (North) Serengeti plains, 2O.iii. 1972, Schmidt 790 (DSM). Togoro Plains, alt. 1600 m, 15.ii. 1968, Greenway &? Kanuri 73792 (EA, M, K). Tabora, mile 46.6 from the Bologonja river via Kleins camp, ah. 1625 m, 30.iv.1961, Gr&rzway 70732 (EA, K). Nata-Ikoma rd, ah. 1525 m, 7.iv.1959, Tanner 4720 (B, BR). Without locality: Ke$ot 3369 (EA). Kuchar 6828 (EA).

T.ERIKSSON

170

Athrotia

gracih (Oliv.)

Mattf. ssp. psyllioides (Oliv.) . nov. (Figure 36B)

Athrofima psyllioides (Oliv.) Mattf. (1936: 302) -Basionym: Oliv. (1894: t. 2293). -Type: Smith ~.n., Kilimanjaro, May

T. Eriksson

stat.

Polycline psyllioides 1893 (K holotype).

Athroisma haareri (Dandy) Mattf. (1936: 302). -PO&line haareri Dandy (1926: 437). -Type: Haare; B 750, Tanganyika Territory: Doinyo Sambu, Arusha, approx. 6000 ft., Feb. 1926 (K holotype). Illustrations.

Oliver

(1894: t. 2293); Blundell

(1987: t. 89 [photo]).

Height c. 20 cm to c. 1 m (fide ~011.). I.W\U not petiolate or shortly petiolate with one or three veins basally. Lamina linear to elliptical c. 2.5-12 x O.l2.5 cm; margin entire, dentate or serrate, involute to slightly revolute. Petiole 0, (-3) mm. URXTS subtending capitula ovate to lingulate (basal) or obovate (median), entire; margins apically irrvolute or flat, slightly ciliate (median) or ciliate to entire (basal), hyaline part narrow to wide. Basal bracts 3-5 x 2-3 mm. Paleae 3-4 x 1.5-2.5 mm; abaxial side of outermost paleae slightly pubescent, of inner paleae glabrous or with a few glands. Anthers l-l .5 mm. Style 2-3 mm. o\‘~s~~;\s+obovate in outline, not or slightly more narrow near middle, l-l.5 x 0.5-l mm, surface tuberculate to rugose; pappoid corona absent or as a (usually incomplete) ring of hairs. Receptacle 2-5 mm. Distribution and habitat Athroisma gracile ssp. psyllioides is distributed towards the Southeast (Fig. 37), through the distribution area of A. hastzjolium and further to the coast of the Indian Ocean in North-eastern Tanzania, at an altitude of 3-2025 m. It has been collected among the grasses Aristida, Cenchrus, Chloris, Digitaria, Echinochloa, Eragrostis, Heteropogon, Latipes, Pennisetum and Sporolobus, alongside herbaceous genera e.g. Barleria, Caralluma, Helichrysum, Heliotropium, Indigofera, Kyllinga, Leonotis, Ocimum and Pentanisia; among trees and shrubs such as Acacia, Balanites, Car&a, Combreturn, Comm$hora, Cordia, Ecbolium, Euphoriba, Grewia, Hyphaene and Scutia. Notes Athroisma gracile ssp. psyllioides differs from ssp. gracile on the tuberculate to rugose cypselas, a character also shared by A. hastifolium. Also, it usually has wider leaves which are more or less distinctly serrate. A single collection (Bally 13774) has wide leaves with short glandular hairs. It lacks female florets, however, as well as uniseriate hairs. See species delimitation section for further discussion on this taxon. Vernacular names: Cheplelmetiet or Cheplelelmetiet-Ab-Tirita (Kipsigis); Ol’eturot, Olkivire lekima, or Eneyarat (Masai). Collections examined (102) KENYA, EASTERN, KITUI DT: Kitui, in villages, vi.1877, Hildebrandt 2708 (BM, W). MACHAKOS DT: Thika-Mwingi rd, W of Kithyoko, c. l”7’S 37’47’E, ah. c. 1100 m, 3.iii.1973, Sangai 906 (EA, M). c. 30 km from Nairobi on Mombasa rd, alt. c. 1600 m, 19.vi.1970, Friis 86 (EA). Lukenya, E of Nairobi,

THE GENUS ATHROISMA

171

foot of hill, ah. 1575 m, 12.ix.1954, Bally 9847 (EA, K); ah. 1750 m, vi.1932, Mainwaring 2154 (EA, K); Lukenya Hill, alt. 1525 m, viii.1939, Ba& 773 (EA, K). Mua H’ll1 s, i.1930, Benson s.n. (BM). Katumani Experimental Farm, near Machakos, alt. 1575 m, 28.vi.1958, Bogdan AB4604 (B, EA, FT, K); ah. 1625 m, 26.v.1966, Ndunda KT55 (EA); ah. 1575 m, v.1958, toll. ¬. KEF594 (EA); alt. 1675 m, vi.1967, Iwrens? 2755 (EA). Western division c. 33 miles from the Machakos township, eastern side of the mtns slopes, ah. 1925 m, l.i.1968, Mwangangi 528 (BR, EA). Kilima Kiu, 1926, Prescott De& s.n. (BM); ah. 2025 m, 16.ii.1972, Kokwaro 3037 (BR, EA). Kilima Kiu Ranch, near small mountain, 1’45’s 37”14’E, 9.vi.1974, GiZZett 20707/A (EA). Kilungu location, Kithembe hill above Kyamwiitu communal spring on KithembeIthemboni rd, alt. 1825 m, 7.vi.1982, Mwangungi 2333 (EA). Sultan Hamud, 22.iv.1902, Kaessner 660 (BM, Z). Emal-Garabani, alt. 1525 m, vii.1940, Opiko 296 (K). Kibwezi, alt. c. 1000 m, 28.i. 1906, Schefir 72 (BM, E, G, K, L, P, S, W, Z); 12.xi.1910, SchejZer 470 (BM, C, E, G, L, P, S, W, 2). Mtito Andei, alt. 750 m, i.1950, BaZZy 7709 (EA, G, K); alt. 725 m, ii.1963, Tweedie 2555 (K). CENTRAL, NAIROBI D-T: Nairobi, Lone tree, ii.1938, BaZZy 6897 (EA, K); near Linn Depst. (?), 27.vi.1986, Mosinde IM53 (EA); Nairobi Nat. Park, 23.~. 196 1, l’erdcourt & PoZhiZZ 3 752A (EA). Rrr;-I- VULEY, KAJIADO DT: Suswa, 13.iii.1964, Glover &? Bledonet 4355 (EA). Kapiti Plains, 1893, Gregory 702 (BM). Ngong escarpment near Nairobi, alt. 1825 m, 7.vi. 1947, BaZb 503 7 (G, K). Ngong hill slopes, S side, 19.viii.1952, Verdcourt 685 (EA, FT); SW side, ah. 1700 m, 4.viii.1968, GiZZett 78690 (EA, K); W side, l”25’S 36’38’E, alt. 2025 m, 3.ix.1965, Kokwaro, Kanuri & Mathenge 320 (EA, K). NairobiMagadi rd, alt. 1400 m, 25.viii.1963, MacKinnon 8K (E); MacKinnon 77 (EA); mile 35, 25.v.1958, Nupper 729 (BR, EA, K, UPS); c. mile 50 from Nairobi, 8.iv.1956, Greenway 8987 (EA, K); Olengejepa area c. 15 miles from Magadi, ah. 925 m, 30.vi.1962, Glover &? Samuel 2973 (EA, K). Kajiado, 15.iii.1964, Lind, Agnew & Beecher 5700 (EA); 8.vi.1975, Kokwaro 3772 (EA). 1 mile Kajiado-Namanga rd, roadside, 27.vi.1970, Kabuye 759 (BR, EA, SRGH). Kajiado-Namanga rd, 7.v.1977, Kokwaro 4067 (EA); 5.vii.1977, Kokwaro 4087 (EA); 15.vi.1957, Greenway 9797 (EA, K); Mile 40 Namanga-Nairobi, ah. 1525 m, 26.vi.1961, Lind 3776 (K). Oloitokitok, alt. c. 1900 m, 26.iv.1934, Schlieben 5737 (BR). NAKURU DT: 01 Longonot estate, ah. 1900 m, 3.i.1962, Kerfoot 3483 (EA). NAROK DT: Near Loita Hills, 01 Kilo&i, ah. 1600 m, 12.vii.1975, BaZly 76906 (BR, EA, K). 27 km W of crossroads on NarokKeekorok rd, c. l”21’S 35”38’E, alt. 1940 m, 2.ii.1983, &ZZett 24034 (EA, K). Aitong area, alt. 1750 m, 19.iv.1961, Glover, Gwynne @ Samuel 386B (EA). Mara, Swyneatoni Hill, ah. 1525 m, 8.ix.1967, Ahiti 54 (EA); Ahiti 724 (EA). Masai Mara Nat. Reserve, Keekorok, alt. 1575 m, 19.ix.1947, BaZZy 5478 (C, G). Inexact localities: Roadside in the Rift valley, ah. 1750 m, 2O.ix.1930, Napier 472 (BM, BR, EA, K). M asailand, roadside, ah. 1825 m, 15.iv.1961, Glover, Gwynne & Samuel 527B (EA, K). COAST, T~UTA DT: Tsavo Nat. Park East, Worssera area, 1965, Hucks & Hucks 703 (EA); 3.9 miles W of Voi gate along pipeline, alt. 475 m, 5.i.1967, Greenway &’ Kunuri 72965 (EA, FT). 13 miles on Voi-Taveta rd, ah. 750 m, 12.xii.1961, PoZhiZZ & Paul0 970 (B, BR, EA, IT, M, S). B ura station, 18.vii. 1956, Semlingwa 27 (EA, K). Grasslands at Bura hills, ah. 1200 m, vii.1897, Sacleux 2283 (I?). Taita Hills Lodge, UTM 37MDG1711, ah. 925 m, 7.viii.1979, Kuchar 72050 (EA). Without precise

T. EFUKSSON

172

Decie s.n. (BM). T~\N~I~~YI!\, ARUSHA, ARULJERU DT: By Richards 23359 (K). the rd to Ngare Nanyuki,. alt. 1524 m, 15.xii.1968, Cldonyo Sambu, ah. c. 1825 m, ii.1926, Huarer B750. (K); alt. c. 1675 m, vi.1927, Haarer 265 (BR, EA, G, P). W of Arusha to Namanga rd, near Lengijave village before Oldonyo Sambu, C. 3”13’S 36”36’E, alt. 1640 m, 7.vi.1990, Eriksson, Kulema & Leliyo 507 (NHT, S). Without locality, 10.x.1974, K&wa 748 (K). MO~WJLI D-r: A weed in pasture on Ngaserai plain, 26.iv.1962, van Rensburg 686 (EA). Track to Ketumbaine and Gelai, alt. 1219 m, 1 l.i.1969, Richards 23774 (EA). Foot of Lengijabi, 4.viii.1904, UhZig 204 (W). Ngorongoro Cons. area, near Lemuta hill, 21.iii.1966, Herlocker 384 (EA). Olduvai, alt. 1520 m, 23.vi.1970, Harris BJH 4878 (DSM). KITETO DT: Sanya plains, Arusha rd, ah. c. 925 m, vi.1927, Haarer 303 (EA, K). Simanjiro plains, v.1971, Kahurananga 2263 (NHT); 25. xi.1977, Kibuwa 2887 (NHT). S. MasaiEngii, ah. 1525 m, ii.1977, Peterson 270 (EA). Mlayas (Mloyas?), ll.vii.1906, Jaeger 85 (P, Z). H AMNG DT: Tarangire Nat. Park, rd to Babati, 1066 m alt., ll.ii.1970, Richards 25377 (EA, K). KIL~LWJARO, Hru D-r: 01 Molog, alt. 1500 m, i.1909, Endlich 749 (M, W). Rongai Ranches, on edge of soda lake, alt. 1375 m, 28.xii.1957, Lind 2259a (K). Dutch Corner, Sanya juu, grid BG805 521, ah. 1400 m, 16.vii.1967, Bigger 7200 (EA). Sanya Juu, slope between the road and the stream Sanya, c. 3’11’s 37”04’E, alt. 1240 m, 15.vi.1990, Eriksson, Kalema &’ LeZiyo 557 (NHT, S). MOSHI DT: Himo, ah. 1100 m, vii.1893, VoZkens 570 (BM, BR, G). Moshi, ah. c. 750 m, viii.1927, Huarer 582 (EA, K). P~\RE DT: N. Pare Hills, plain W of Lake Jipe, 14.ii.1970, Bully 73774 (EA, G). Grasslands on E side of Pare, alt. c. 900 m, 14.xii.1901, UhZig 875 (EA). P are, alt. 925 m, vii.1925, Huarer 3 (K). Moshi-Same rd, c. 10 km S of Mwanga, c. 3”44’S 37”36’E, 16.vi.1990, Eriksson, Kalema & Leliyo 559 (NHT, S, TEX). N. Pare Mts, Lembeni towards the mountains, alt. 950 m, 19.vi.1926, Peter 46668 (BR). Lembeni, all. c. 850 m, xii.1927, Haarer 966 (EA, K). c. 1 mile S of Lembeni, alt. 925 m, l.i.1970, BaZZy 873 (K). MoshiSame rd, c. 18 km S of Lembeni, c. 3”56’S 37”40’E, alt. 970 m, 16.vi.1990, Eriksson, Kalema &? LeZiyo 560 (NHT, S). Himo-Same, alt. c. 760 m, 6.vi.1970, Mwa-sumbi, Harris & Tadros LBM70874 (DSM, EA). Same township, near Same Elephant Hotel, ah. c. 900 m, 9.viii.1984, Mwasumbi &’ Leliyo 72570 (DSM). S. Pare mountains, gentle hill slopes, Vudee valley, alt. 850 m, l.vii.1942, Greenwuy 6577 (EA, K). I nexact locality: Kilimanjaro, v. 1893, Smith s.n. (K). TANGA, KOROGWE DT: Buiko, 3.vi.1916, Buchanan s.n. (BM). Mombo, 4.X.1905, Engler 3372 (EA); 6.viii.1908, Braun 7973 (EA); near U.M.C.A. Church, 14.viii.1966, Semsei 4086 (BR, EA, K, LISC, UPS). Mombo-Makuyuni, km 125, alt. 400-440 m, 30.v.1926, Peter 40676 (EA, K); alt. 375 m, 1 l.ix. 1935, Greenway 4074 (EA, K). PANGANI DT: Cove near mouth of Pangani river, backshore area, alt. 3-4 m, 22.vi.1968, Gilbert 3076 (EA). HI-\NDENI DT: Woodland near Handeni town, alt. 600 m, 14.vii.1982, Mugogo 2782 (EA, NHT) . locality:

1914,

Prescott

Athroisma fanshawei Wild (Figure 38) Wild (1980: 18). -Type: 30/3/63 (SRGH holotype;

Funshawe 7752, Northern K, IUD0 [fide Wild lot.

Rhodesia, Nodola cit.] isotypes).

rural,

THE

GENUS

ATHROISM

173

A

F

Figure 38. Alhroima fanshawei. A, flowering subtending bract; F, palea; G, hermaphrodite 7752). Same scale as in Fig. 23.

branch; floret;

G

H

I

B, basal subtending bract; C, median H, twin hair; I, anther (A-I Fan&awe

T.ERtK!SON

174

Autapomorphy

not mentioned

in description:

Corolla

shorter

than cypsela.

Erect, c. 30-45 cm high, annual herbs. Stems and branches glabrous, green, becoming brownish or pinkish. Rhizome absent. LEAVES not petiolate, glabrous, basally one-veined. Lowermost leaves not remaining when dry. Lamina entire, linear, c. 4.5-6.5 x 0.1 cm, +chartaceous; apex acuminate, not apiculate; base attenuate. Petiole absent. Leaves reach c. 15margin entire, involute; 35 mm below the glomerule, of normal size. SYNFLORESCENCES dichasial, of branches slender, glabrous. CLO~RULES c. lo-12 mm, l-3 glomerules; ‘containing c. 30-40 white to pinkish capitula. CAPITUL~~ 2 mm wide, without female florets, with c. 5-8 hermaphrodite florets. BRAC:TS ovate to obovate; apex acute; margins apically involute, not or slightly ciliate basally, hyaline part narrow but distinct; both sides glabrous. Median bracts 5 x 2.5 mm. Basal bracts c. 6 x 3-4 mm. INVOLUCRAL BRACTS absent. PALEAE obovate, 5 x 2.53 mm; apex& truncate, unlobed; abaxial side glabrous or glandular with a few small hairs on vein. COROLLA of hermaphrodite florets 1.5-2 x 1.5-2 mm; Anthers 1.1 mm; tails 0.2 mm. Style 1.5 mm. c\;PsErAs tube glandular. narrowly obovate in outline, narrow near middle, 2.5-3 x 1 mm, with scattered hairs, glandular apically; lateral ridges indistinct; surface smooth; twin-hairs c. 0.3-0.5 mm long, with much recurved apical branches; pappoid corona as a ring of basally connected hairs and very narrow scales; neck c. 0.1 mm. Receptacle of unknown length. Distribution and habitat Athroisma fanshawei has been collected only once in eastern Zambia 39) and it was recorded as a semi-aquatic herb found in a shallow Flowering in March.

(Fig. pan.

Notes The linear leaves of this species make it somewhat similar to some specimens of A. gracile from which it is easily distinguished on the annual habit and on bearing leaves only on the apical part of the plant. Its large cypselas and the corollas which are shorter than the cypselas are unique within the genus. A. fanshawei shares some features with A. stuhlmannii: the annual habit, and the cypselas being more narrow near the middle; but A. fanshawei is distinguished on its long pedunculoid branches. The variation of this species is unknown due to the meagre material. No collections

except

type. Athroisma

stuhlmannii 0. Hoffm. (Figure 40)

Hoffrnann (1894: 233). -Type: Stuhlmann 4794, Centralafrikan. Seengebiet: Seeke, 3 1. Mai 1892 (B holotype t) -Eriksson, Kalema & Leliyo 538, Tanzania, Arusha, Hanang Dt: Arusha-Dodoma rd c. 5 km NE of Magugu, alt. 920 m, c. 3”58’S, 35’47’E, 12. Jun. 1990 (B neotype, designated here; NHT, S duplicates).

THE

GENUS

ATHROISMA

Figure 39: Known distribution of Athroisma fanshawei (A). The map shows the coast of south east Africa.

(*), A. stuhlmannii {a),

and

A. ineuitabile

Note. I have been unable to find the type indicated by Hoffmann. It was probably destroyed in 1943 (Hiepko, 1978). In some cases duplicates of Stuhlmann’s collections may be found in HBG (Gillett, 1962), but this specific collection is not present there (H. H. Poppendieck, in litt.). No other collections were mentioned by Hoffmann, hence I designate a neotype. The description by Hoffmann is undoubtedly of this species. Erect or rarely prostrate, 15-c. 50 cm high, annual herbs. Stems and branches glabrous, yellowish green, becoming pinkish at base. Rhizome absent. LEAVES indistinctly petiolate, glabrous, basally three-veined. Lowermost leaves not remaining when dry. Lamina entire, narrowly ovate to narrowly obovate.

T. ERIKSSON

176

Figure 40. Athroirma stuhlmannii A, flowering subtending bract; F, palea; G, hermaphrodite B Ochieng 2; C Rehnsburg 33; F, G, I Eriks~on

branch; B, basal subtending bract; C, median floret; H, twin hair; I, anther (A Tanner 4087; et aL 539; H Guy 2OOq. Same scale as in Fig.

23.

3.5-8.5 x 0.5-2 cm, chartaceous; apex obtuse to acute, apiculate or not; margin unevenly serrate, flat to slightly involute; base attenuate; teeth apiculate or not. Petiole almost absent or up to 17 mm. Leaves reach O-2 mm below the glomerule, of normal size. SYNFLORESCENCES monochasial or dichasial, of 2-30 glomerules; branches, when present, robust, glabrous. GLOMERULES solitary at nodes, 9-18 mm, containing (14-)30-35 white to purplish capitula. CAPITULA 3-4 mm wide, without female florets, with 8-25 hermaphrodite florets. BRACTS ovate to lingulate (basal) or obovate (median), entire; apex acute to acuminate; margins apically involute, ciliate to entire, hyaline part wide; both sides glabrous. Median bracts 3.5-4.5 x l-2.5 mm. Basal bracts 4-5.5 x 2-4 mm. INVOLUCRAL BRACTS absent. PALEM obovate to rectanguloid, 2.5-4 x l-2.5 mm; apex truncate to unevenly erose or indistinctly lobed; abaxial side glabrous. COROLLA of Hermaphrodite florets 1.5-2(-2.5) x lI.5 mm; tube glandular. Anthers O-9-1.2 mm; tails 0.1-O-2 mm. Style l.52.5 mm. CYPSELAS slightly obovate in outline, more narrow near middle, l1.5 x 0.5 mm, with scattered hairs, glandular apically, along margins, and

THE GENUS Ai’HROISMA basally; lateral ridges indistinct; surface smooth; twin-hairs 0.1-0.2 recurved apical branches; pappoid corona as af complete ring connected hairs; neck 0.1 mm. Receptacle 3-4 mm.

177

mm, with of basally

Distribution and habitat This species is distributed in an area southeast of Lake Victoria where it is reported to be common locally. It has also been found twice in Zimbabwe and once in Northern Zambia (Fig. 39). It is found in wet habitats like wet grasslands, marshes, river banks, smaller or as a weed of cultivated fields. It occurs on streams etc., in woodlands, black cotton soil, sandy or clayey soils, with Acacia, Commiphora, Panicum, Sporolobus, Dactyloctenium, and Pennisetum. The altitudes range from c. 1000 m up to 1275 m. It has been collected in flower mostly from April to late June but a few collections are from other parts of the year (February in Zimbabwe; October in Zambia; December in Kenya). Notes It is easily distinguished from all other species in the genus on the consistently sessile glomerules at the branching nodes. Vigorous specimens thereby contain a large number of glomerules which are scattered almost evenly throughout the plant, some quite close to the ground. All other species except A. inevitabile have glomerules which are always set on distinct pedunculoid branches. The branching is very regular in A. stuhlmannii. It is cyme-like as usual within the genus, and very regularly dichasial-or monochasial towards the apex of the shoots. Such branching is also found in apical branches of A. ineuitabile. It has a carrot-like aroma when fresh, something which has also been observed in A. ineuitabile. Vernacular name: Inunghi (Tanzania, Mwanza). Chromosome number 2n = 20 (Acquisition nr. SU-S-900709.16, seed from Erikson et al. 547). Collections examined (24) KENYA, NYAIVZA, Krsui~ru DT: Nyalenda-Kisumu, ,l 1.xii. 1968, - Kokwaro 7653 (EA). Kib OS, ah. 1175 m, xii.1965 Bradley K30 (EA). Sugar Research Station Kibos, alt 1203 m, xii.1976, Ochieng 2 (EA). Nanga, viii.1934, Turner 6790 (EA, K). TANZANIA, ARUSHA, I-&WANG DT: Arusha-Dodoma rd c. 5 km NE of Magugu, alt. 920 m, c. 3”58’S, 35”47’E, 12.vi.1990, Eriksson, Kalema G’ LeZiyo 538 (B, NHT, S); Erikzon, Kalema & LeZzjo 539 (S, TEX); 13.vi.1990, Erikson, Kalema &’ LeZzjo 547 (S); 4 miles N of Magugu, ah. 1050 m, 21.iv.1964, Welch 569 (BR, EA, K); 94 miles S of Arusha, ah. 1075 m,. 7.v.1962, PoZhiZZ G? Paul0 2376 (B, BR, EA, K). Ma, Musohl~ DT: Maji Moto, Ngereme, alt. 1275 m, 6.iv.1959, Tanner 4087 (BR, K, SRGH). SERENGETI DT: Serengeti Nat. Park, western corridor, ah. 1160 m, 22.vi.1970, Harris @ Harris BJH4850 (EA, DSM). MWAIVZA, MWAIIZA DT: Mwanza, 1925, Davti 36 (K). 15 miles S of Mwanza, v.1931, Haarer 2073 (BR, EA, K). Liyoma, Urima, ah. 1125 m, 4.v.1952, Tanner 709 (BR, K, M). Usukuma

T. ERIKSSON

178

(Sukuma), 26.iv.1935, Staples 426 (EA). SHIFN.WGA, MAS\VA D-T: Malya, 26.iv.1959, Yeoman 25 (EA). SHINY~~CA Dr: Seke, 3 1.v. 1892, Stuhlmann 4794 (Bt, not seen). Magagi, ah. c. 1180 m, xii.1971, Stefnescu & Zikumbona 795 near river, (DSM). Near Negezi, 19.vi.1945, Rehnsburg 33 (EA). Shinyanga, ah. 1100 m, 19.v.1931, Bwtt 2390A (BM, EA, K). SINGIDA, SINGIDA DT: 7 miles on Bahi-Kilimatinde rd, 5”54’S 35’14’E, alt. 850 m, 18.ix.1988, Bidgood, Mwusumbi & Vollesen’ 7202 (K). TABORA, TA~OIII\ DT: South Tabora, 26.vi.1938, Lindeman 684 (BM, EA). ZAMBIA, NOR.I.HERN: Mbesuma (or Chunga), on banks of Kalungu river, alt. 1175-1200 m, 14.x.1961, Astle 962 (K, SRGH). ZIMBABWE, MASHONALXID WEST: Hurungwe, Mana Pools game reserve, ii.1972, Guy 2000 (BR, K, M, SRGH). Sengwa research station, 8.iv.1969, Jacobsen 577 (SRGH).

Athroisma inevitabile T. Eriksson

sp. nov.

(Figure 4 7) Type: LewaZZe 2677, Rwanda, Kibungu, Rwinkwavu, S de la Kagera, au bord d’une mare sur laterite, altitude 1400 m (BR holotype; isotypes). Autapomorphies not mentioned shorter than basal ones.

in description:

apical

pedunculoid

Diagnosis. A Athroismate stuhlmanii ramis pedunculoidibus brevibus distinctis, longitudine gradatim apicem surculi versus decresentibus

savane EA, K branches

quanquam differt.

Erect (or erect from a +decumbent base), 20-80 cm high, annual herbs. Stems and branches glabrous, green, becoming brownish or purplish. Rhizome absent (present in one ~011.). LEAVES not or indistinctly petiolate, glabrous, basally three-veined. Lowermost leaves not remaining when dry. Lamina entire, linear to elliptic, narrowly obovate or narrowly ovate, c. 3.5-10 x 0.31.5(-3) cm, chartaceous; apex acute to acuminate, not or indistinctly apiculate; margin serrate to subentire, involute (in narrow leaves) to flat; base attenuate; teeth not apiculate. Petiole absent or up to 15 mm. Leaves reach c. l-83 mm below the glomerule, of normal size. SYNFLORE~CENCES monochasial or dichasial, of l-5 glomerules; branches slender to robust, glabrous. GLOMERULES 9-15 mm, containing c. 30-40 white to purplish capitula. CAPITUIA 2-3 mm wide, without female florets, with 11-15 hermaphrodite florets. BRACTS ovate to lingulate (basal) or obovate (median), glabrous; apex& acute to acuminate; margins apically involute, entire, hyaline part narrow to almost absent; both sides glabrous. Median bracts 3.5-5 x l-l.5 mm. Basal bracts 3-5 x 2-3 mm. IIWOLUCFLAL BRACTS absent. PALEAE obovate to rectanguloid, 3 x l-2 mm; apex * truncate, unlobed, slightly erose; abaxial side glabrous. COROLLA of hermaphrodite florets 1.5-2 x 1.5 mm; tube glandular. Anthers 1 mm; tails 0.1-0.3 mm. Style 1.5-2 mm. CYPSELG obovate to elliptic in outline, some narrow near middle, 1 x 0.5 mm, with scattered hairs, glandular at least apically and basally; lateral ridges indistinct; surface smooth; twin-hairs 0.1 mm, with recurved apical branches; pappoid corona absent, or with a few hairs in an uneven ring; neck, 0.1 mm. Receptacle 2-4 mm.

THE

GENUS

ATHROISMA

Figure 41. Athroima inevitabile sp. nov. A, flowering branch; B, basal subtending bract; C, median subtending bract; F;palea; G, hermaphrodite floret; H, twin hair; I, anther; J, Leaf (A, C, F, G, I Lewalle 2677; B, J Troupin 15032; H Chandler 866). Same scale as in Fig. 23, scale of J = A.

179

180

T.ERIKSSON

D&rib&ion and habitat Athroisma inevitabile is distributed on the western side of Lake Victoria (Fig. 39) approximately opposite to A. stuhzmanni~ to which it is related. It is common but sparse in wet (savanna) grasslands and swampy areas; at the margin of pans (ponds) or rivers. Altitude 1100-1400 m. Reported on lateritic, sometimes rocky, soil with grass-like genera such as Cyperus, Digitaria, Panicum, more or l&s herbaceous genera including Achyranthes, Ammannia, Aneilema, Bidens and other Asteraceae genera, Biophytum, Euphorbia, Lantana, and Scrophulariaceae genera. The collections have been made throughout the year except March, July, and October. Notes kthroisma inevitabile is quite similar JO A. stuhlmannii: it is a glabrous annual in wet situations, has similar branching pattern and short pedunculoid branches, leaves (at least basally) and details of the capitula. It differs, however, by having distinct and sometimes quite long pedunculoid branches on the lower parts of the plant. In addition, the leaves are usually more narrow and longer. Typical for A. inevitabile is the rather wide basal leaves which rapidly decrease in width towards the apex of the plant. Also, the length of the pedunculoid branches generally decreases towards the apex of the plant. The apical portions of the branches may thereby be very similar to those of A. stuhlmannii. It has more than once been reported to possess a carrot-like aroma when fresh (cf. A. stuhlmanniz]. A. inevitabile looks much like an intermediate between A. gracile and A. stuhlmannii (see species delimitation section for further discussion on selection of rank for this taxon). Collections examined (14) UGANDA, NORTHERW Lango, Achua (Assua) river, on way to Kitgum, Liebenberg 246 (BR, EA, K). AVKOLE: Ishingiro, alt. 1375 m, v.1939, Purseglove P707 (K). EASTERX Teso, Serere, alt. 1100 m, xi.1931, Chandler 58 (K); viii.1932, Chandler 866 (BM, BR, EA, K, S). BUSOGA: Bulamogi, Bugonzo, 4 mls W of Kaliro just N of road to Kamuli, alt. 1075 m, 17.ix.1958, Wood 387 (EA); In th e middle of Kaliro A. L. G. Plantation 1 mile SW of the township, 16.v.1953, Wood 747 (EA, BR, K). RWANDA, BYUMBA: Kagera Nat. Park, Matinza plateau, alt. 1400 m, 14.iv.1969, Bouxin @ Radoux 181 (BR); 15.i.1972, Aquier 225.5 (BR). KIBUNGO: Kagera Nat. Park, Kabuga peninsula at lake Ihema, alt. 1350 m, l.v.1973, Troupin 75032 (BR); Lulenge peninsula at lake Ihema, ah. 1350 m, 15.viii.1974, van der Veken 70879 (BR). Between Muchuchu and Murwita, alt. 1300 m, i.1938, Lebrun 9678 (BR, K, P). Rwinkwawu, S of Kagera, alt. 1400 m, 30.xii.1967, &ewaZZe 2677 (BR, EA, K). Rwinkwavu, Nyakora valley, 4 km S of the Nat. Park, 1”57’S, 30”40’E, ah. 1320 m, 25 vi.1978, Raynal 20709 (K).-TANZANIA, KIGOMA, KICOA,~~~DT: Beside the river a$ Uvinza, 24.ii.1958, Friend 36 (EA, K).

THE

GENUS

ATHROISMA

181

ACKNOWLEDGEMENTS

I thank Dr A. Anderberg and Prof. B. Nordenstam for help, discussions and interest throughout the entire project and for comments on earlier drafts of this paper. I am grateful to the Directors and Curators of the herbaria who have supplied generous loans, and helped during visits. I thank MS M. van Dierendonck, Prof. P. Hiepko, Dr M. Kallersjo, Dr J. Klackenberg, Dr P. 0. Karis, Mr B. Mhoro, Mr P. Nordesjo, Dr A. Tehler, and Dr M. Thulin for miscellaneous help during this study. Economic support from the Swedish Natural Science Research Council (grant for Compositae taxonomy), the Royal Swedish Academy of Sciences (Enanderska fonden and H. E. minnesfond), the Uddenberg-Nordingska foundation, and Johanssons Stockholm University (C. F. Liljevalchs Jr. fond) is gratefully acknowledged. Lastly, I thank the Tanzania Commission for Science and Technology, and the Office of the President in Kenya, for allowing me research clearance in their respective countries. REFERENCES Agnew ADQ 1974. Upland Kenya Wild Flowers. Oxford: Oxford University Press. Anderson E. 1949. htrogressive Hybridization New York: John Wiley & Sons. Anderson LE. 1954. Hoyer’s solution as a rapid mounting medium for bryophytes. Btyologist 57: 242247. Archie JW. 1989. A randomization test for phylogenetic information in systematic data. Systematic Zoology 38: 219-252. Amott GAW. 1838. Observations of some new or obscure species of plants. No. 1. Magazine of zoology and botany 2: 419-427. Backer CA, Bakhuizen van den Brink RC. 1965. Flora of Java 2. Groningen: Noordhoff. Bamps P. 1968. Flare du Congo du Rwanda et du Burundi, Index des lieux de recolte. Bruxelles: Jardin botanique national de Belgique. Bartholomew JC ed. 1990. The Times Atlas of the World, comprehensive ed, 8th edition. London: Times Books. Bentham G. 1873. Compositae. In: Bentham G, Hooker JD, eds. Genera plantarum 2. London: Love11 Reeve, Williams & Norgate, 163-533. Blundell M. 1987. Collins guide lo the wild jlowers of East Africa London: Collins. Bremer K. 1987. Tribal interrelationships of the Asteraceae. Cladr&s 3: 210-253. Bremer K. 1988. The limits of amino acid sequence data in Angiosperm phylogenetic reconstruction. Evolution 42: 795-803. Brummitt RK, Powell CE (eds) 1992. Authors of Plant Names. Kew: Royal Botanic Gardens. Candolle AP, de. 1833. Genres nouveaux a la famille des Composees ou Synantherees. Seconde decade, Archives de Botanique 2: 5 14-5 19. Candolle AP, de. 1836. Prodromus systematis naturalis regni vegetabilic 5. Paris: Treuttel & Wiirtz. Chiovenda E. 1916. Le collezjoni botaniche, Result&i scientifici della missione Stefanini-Paoli nella Somalia Italiana 1. Firenze: R. Istituto di studi superiori, praticie di perfezionamento in Firenze. Chiovenda E. 1931. Vegetali utilizzati nella medicina indieena dell’Eritrea. Somalia. e reeione vicine. ” Atti Aimo Congressso Skdi Coloniali, Firm 1931: 351-375. Chiovenda E. 1932. Flora Somala 2. Modena. Clarke CB. 1876. Compositae Indicae, descn$tae et secus Genera Benthamii ordinatae. Calcutta. Cracraft J. 1989. Speciation and its ontology: The empirical consequences of alternative species concepts for understanding patterns and processes of differentiation. In: Otte D, Endler JA, eds. Specialion and its consequences. Sunderland: Sinauer Associates, 28-59. Cufodontis G. 1943. Note di floristica Africana (l-5). Nuovo giomale botanico ilirliano 50: 100-120. Dandy JE. 1926. Polycline Haareri. In: Decades Kewenses plantarum novarum in herbario hortii Regii conservatorum. Decas CXV. Bulletin of miscellaneous information, Kew. 10: 433-440. de Queiroz K, Donoghue MJ. 1990. Phylogenetic systematics or Nelson’s version of Cladistics? Cladistics 6: 61-75. Donoghue MJ, Olmstead RG, Smith JF, Palmer JD. 1992. Phylogenetic relationships of Dipsacales based on rbcL Sequences. Annals of the Missouri Botanical Garden 79: 333-345. Dormer KJ. 1962. The fibrous layer in the anthers of Compositae. New Phytologist 61: 150-153.

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APPENDIX List Taxa

which

[Kiheocephalus [K’deocephalus

are not accepted

are’ within

square

Gagnep. = Adrobma] fhorelii Gagnep. = A. laciniatum]

of lwa brackets

184

T. EFUKSSON

Athroisma Athroisma [Athroisma Athroisma Athroisma Athroisma

DC. boranenx Cufod. boranense Cufod. var. hispidum Cufod. = A. boranensej fanshawei Wild gracile (Oh.) Mattf. gracile (Oh.) Mattf. ssp. gracile Athrokma grucile (Oliv.) Mat& ssp. &yZZioih (Oliv.) T. Eriksson stat. nov. [Afhroisma haareri (Dandy) M/attf. = A. gracile ssp. p$lioidd Athroisma hastifolium Mattf. Athroisma inevitabile T. Eriksson sp. nov. Athrokma luciniatum DC. Athroisma lobatum (Klatt) Mattf. Athroisma pinnat$dum T. Eriksson sp. nov. Athroirma proteiforme (Humbert) Ma&f. Athroisma psilocarjum T. Eriksson sp. nov. [Athrokma pyllioides (Oliv.) Mattf. = A. gracile ssp. psyllioides] Athroisma pusillum T. Eriksson sp. nov. [Athroisma sp. A. sensu Agnew = Intermediates between A. gracilz and A. boranense Athhisma stuhlmannii (0. Hoflin.) Mattf. [Athroixma viccidum Zoll. & Moritzi = A. kzciniatum]. [Blepharispermum lobatum Klatt = A. lobatum] [PO&line gracilis (Oliv.) Oliv. = A. gracile ssp. gracile] [Polycline haareri Dandy = A. ,q-a& ssp. psyllioidesl [Pol&ne haareri Dandy var. ~avellensis &I& = A. ioranense] [Polvcline lobata (Klattl Chiov. = A. lobatuml [Pot$cline Oliv. L Athksma] [Polycline proteiformti Humbert = A. protezjkmej [PO&line psyllioides Oliv. = A. grade ssp. psyllioides] [Sphaeranthus gracilti Oliv. = A. gracib ssp. gracile] [Sphaeranthus kzciniatus Wall. = A. laciniatum]

(groupA!Z)]