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Fungal portraits
Vol 9 (4)
FUNGAL PORTRAITS No. 36: Cotylidia pannosa sensu auct. Alick Henrici
Fig. 1. Cotylidia pannosa? - possibly a colour form, possibly a related species. Found by members of the North West Fungus Group in broadleaf woodland near Keswick in Cumbria, 6 Sept. 2007. The rosette shown is about 5 cm across. Communicated to Kew by John Taylor. Photograph © Len Worthington.
f ever a collection exemplified the joy of foraying and the despair of identification then this must be it. The North West Fungus Group were holding a weekend residential foray based at Keswick in the Lake District in September 2007. Beside a path in soil in mixed broadleaf woodland they suddenly came on six or seven spectacular rosettes of the species illustrated in Fig. l. Nobody had any idea what it was. This is hardly surprising given that the full resources of Kew herbarium and library have also failed to provide a fully satisfactory identification. On morphological grounds this species clearly belongs somewhere in the assemblage treated by Reid (1965) in his Monograph of the Stipitate Stereoid Fungi. As the title
I
suggests, Reid covered species with the smooth hymenium of a Stereum, and likewise with smooth hyaline spores, but growing ± stipitate from soil or on moss or buried wood. There are very few such species in Europe and nearly all are rare everywhere; this is a growth form commoner in the tropics. Reid erected the family Podoscyphaceae to cover most of this group. Some Thelephora species have a similar growth form but these have brown warted spores and are clearly quite unrelated. Five British species have been assigned to the Podoscyphaceae and only two of these form substantial rosettes. The better known of these two is Podoscypha multizonata - see for instance the recent account in Field Mycology by Overall & Mottram (2006). It
111
Vol 9 (4) tends to be larger, tougher and duller coloured than the species in Fig.1. More crucially it has abundant skeletal hyphae and clamps on the generative hyphae, while Peter Roberts at Kew has found no skeletals or clamps in the present material. The other rosette former is the rather poorly known Cotylidia pannosa (Sowerby) D.A.Reid, illustrated in Fungi of Switzerland Vol.2 (BK2/184) and with detailed drawings in Corticiaceae of North Europe Vol.3. This is a good fit microscopically, but is described by Reid as “pure white when fresh but rapidly assuming a dingy yellowish tinge on weathering”. Reid assigned over 20 British collections to C. pannosa in his monograph, including fresh material he collected himself in Burnham Beeches in 1953. He makes no mention of red colouration, nor does any other author I have consulted. However a search under this name on Google Images brought up similar bright red collections assigned to C. pannosa photographed in Spain and Italy. I speculate that this is a different alien species, recently arrived in Europe. If this is its typical appearance it could not have gone unnoticed for long! I am assured that the colours reproduced here are in no way exaggerated, though the dried material is now no more than faintly pink. Without DNA support it would be wrong to claim that this is a new species, but it is still a very notable find even if only a colour form of C. pannosa. In a British context, C. pannosa is among those species with the clearest evidence for a steep decline in its fruiting presence. The forthcoming Red List (available to view online at http://194.203.77.76.fieldmycology/Downlo ad/RDL of Threatened British Fungi.pdf) classifies it as Endangered, based on vouchered records in 21 10 km squares pre1960 but only five post-1960 (and one of these five now known to be a misidentification). For once it is the most recent records that are the more dubious, as the older ones were endorsed by Reid. C. pannosa is known in at least 12 European countries (and for
Reid not known with certainty outside Europe) but is rare in all of them with widespread evidence of decline, causing Ing (1993) to place it as one of only 16 species in his ‘Group A’ characterised by “widespread losses, rapidly declining populations, many national extinctions, high-level concern”. Some history An obvious step to take when investigating whether a bright red fungus can be accommodated within C. pannosa is to consult the type description, or in this case type illustration and accompanying note. C. pannosa was described from Britain in 1799 by Sowerby as Helvella pannosa - the epithet meaning ‘felty’. His plate and text are reproduced here as Figs 2 & 3. He describes it as ‘woody’ (so dimitic?) and he found it in Hampstead, suggesting to me that he might only have had rather depauperate Podoscypha multizonata, present today at several sites in the same area of North London - see Overall & Mottram (2006). Luckily his type material survives, having come via Berkeley to Kew, where it has been re-examined by Peter Roberts for this note and confirmed to be indeed C. pannosa as generally understood. Though P. multizonata is often much larger, the two species can look sufficiently similar for Berkeley also to have been confused. He identified the first material of P. multizonata sent to him as C. pannosa before realising it was different and needing description as a new species. More about the British Podoscyphaceae Podoscypha multizonata is not present in Scandinavia but the other four British species are all described in Corticiaceae of North Europe with detailed drawings, since possibly with corticioid affinities. As with other groups based largely on gross morphology (e.g. polypores, hydnoids) DNA is not proving kind to the Podoscyphaceae. The family is still recognised as a convenience grouping but its members are being gradually reassigned elsewhere. The type genus
112
Vol 9 (4) Podoscypha belongs in or near Meruliaceae in the Polyporales. Of the others, Cyphellostereum laeve (B&K2/233) is a minute pale species growing on living mosses, possibly not uncommon in the wetter parts of Britain, now shown to belong with other moss associates near Rickenella, and thus somewhere in the modern concept of Hymenochaetales. There is a second rare British species of Cotylidia, C. undulata (B&K2/185), the type of the genus, also associated with mosses and also grouping near Rickenella. C. pannosa seems to have a different ecology and may be unrelated. The fifth British species is Stereopsis vitellina, affiliations still unknown, cream-coloured, usually on bare soil, described by Plowright in 1901 from Abernethy Forest, Inverness. It is
capable of forming weak rosettes but has much smaller spores than C. pannosa. It was not found again in Britain until 1999, again in Abernethy Forest, determined by Peter Orton and confirmed by Reid.
Fig.3. The only details provided by Sowerby of his Helvella pannosa.
References Eriksson, J. & Ryvarden, L. (1975). The Corticiaceae of North Europe Vol.3. Oslo, Fungiflora. lng, B. (1993). Towards a Red List of Endangered European Macrofungi. In Fungi of Europe: Investigation, Recording and Conservation. pp 231-237. Royal Botanic Gardens, Kew. Overall, A. & Mottram, K. (2006). Podoscypha multizonata - Zoned Rosette. Field Mycol. 7(3): 82-84. Reid, D.A. (1965). A Monograph of the Stipitate Stereoid Fungi. Nova Hedwigia Beiheft 18. 382pp. Sowerby, J. (1799). Coloured Figures of English Fungi or Mushrooms, Vol.2.
Fig.2. Helvella pannosa, plate of the type reproduced (with kind permission from Botanic Gardens, Kew) from James Coloured Figures of English Fungi Vol.2 (1799).
collection, the Royal Sowerby’s Plate 155
113
FUNGAL PORTRAITS No. 36: Cotylidia pannosa sensu auct. Alick Henrici
Fig. 1. Cotylidia pannosa? - possibly a colour form, possibly a related species. Found by members of the North West Fungus Group in broadleaf woodland near Keswick in Cumbria, 6 Sept. 2007. The rosette shown is about 5 cm across. Communicated to Kew by John Taylor. Photograph © Len Worthington.
f ever a collection exemplified the joy of foraying and the despair of identification then this must be it. The North West Fungus Group were holding a weekend residential foray based at Keswick in the Lake District in September 2007. Beside a path in soil in mixed broadleaf woodland they suddenly came on six or seven spectacular rosettes of the species illustrated in Fig. l. Nobody had any idea what it was. This is hardly surprising given that the full resources of Kew herbarium and library have also failed to provide a fully satisfactory identification. On morphological grounds this species clearly belongs somewhere in the assemblage treated by Reid (1965) in his Monograph of the Stipitate Stereoid Fungi. As the title
I
suggests, Reid covered species with the smooth hymenium of a Stereum, and likewise with smooth hyaline spores, but growing ± stipitate from soil or on moss or buried wood. There are very few such species in Europe and nearly all are rare everywhere; this is a growth form commoner in the tropics. Reid erected the family Podoscyphaceae to cover most of this group. Some Thelephora species have a similar growth form but these have brown warted spores and are clearly quite unrelated. Five British species have been assigned to the Podoscyphaceae and only two of these form substantial rosettes. The better known of these two is Podoscypha multizonata - see for instance the recent account in Field Mycology by Overall & Mottram (2006). It
111
Vol 9 (4) tends to be larger, tougher and duller coloured than the species in Fig.1. More crucially it has abundant skeletal hyphae and clamps on the generative hyphae, while Peter Roberts at Kew has found no skeletals or clamps in the present material. The other rosette former is the rather poorly known Cotylidia pannosa (Sowerby) D.A.Reid, illustrated in Fungi of Switzerland Vol.2 (BK2/184) and with detailed drawings in Corticiaceae of North Europe Vol.3. This is a good fit microscopically, but is described by Reid as “pure white when fresh but rapidly assuming a dingy yellowish tinge on weathering”. Reid assigned over 20 British collections to C. pannosa in his monograph, including fresh material he collected himself in Burnham Beeches in 1953. He makes no mention of red colouration, nor does any other author I have consulted. However a search under this name on Google Images brought up similar bright red collections assigned to C. pannosa photographed in Spain and Italy. I speculate that this is a different alien species, recently arrived in Europe. If this is its typical appearance it could not have gone unnoticed for long! I am assured that the colours reproduced here are in no way exaggerated, though the dried material is now no more than faintly pink. Without DNA support it would be wrong to claim that this is a new species, but it is still a very notable find even if only a colour form of C. pannosa. In a British context, C. pannosa is among those species with the clearest evidence for a steep decline in its fruiting presence. The forthcoming Red List (available to view online at http://194.203.77.76.fieldmycology/Downlo ad/RDL of Threatened British Fungi.pdf) classifies it as Endangered, based on vouchered records in 21 10 km squares pre1960 but only five post-1960 (and one of these five now known to be a misidentification). For once it is the most recent records that are the more dubious, as the older ones were endorsed by Reid. C. pannosa is known in at least 12 European countries (and for
Reid not known with certainty outside Europe) but is rare in all of them with widespread evidence of decline, causing Ing (1993) to place it as one of only 16 species in his ‘Group A’ characterised by “widespread losses, rapidly declining populations, many national extinctions, high-level concern”. Some history An obvious step to take when investigating whether a bright red fungus can be accommodated within C. pannosa is to consult the type description, or in this case type illustration and accompanying note. C. pannosa was described from Britain in 1799 by Sowerby as Helvella pannosa - the epithet meaning ‘felty’. His plate and text are reproduced here as Figs 2 & 3. He describes it as ‘woody’ (so dimitic?) and he found it in Hampstead, suggesting to me that he might only have had rather depauperate Podoscypha multizonata, present today at several sites in the same area of North London - see Overall & Mottram (2006). Luckily his type material survives, having come via Berkeley to Kew, where it has been re-examined by Peter Roberts for this note and confirmed to be indeed C. pannosa as generally understood. Though P. multizonata is often much larger, the two species can look sufficiently similar for Berkeley also to have been confused. He identified the first material of P. multizonata sent to him as C. pannosa before realising it was different and needing description as a new species. More about the British Podoscyphaceae Podoscypha multizonata is not present in Scandinavia but the other four British species are all described in Corticiaceae of North Europe with detailed drawings, since possibly with corticioid affinities. As with other groups based largely on gross morphology (e.g. polypores, hydnoids) DNA is not proving kind to the Podoscyphaceae. The family is still recognised as a convenience grouping but its members are being gradually reassigned elsewhere. The type genus
112
Vol 9 (4) Podoscypha belongs in or near Meruliaceae in the Polyporales. Of the others, Cyphellostereum laeve (B&K2/233) is a minute pale species growing on living mosses, possibly not uncommon in the wetter parts of Britain, now shown to belong with other moss associates near Rickenella, and thus somewhere in the modern concept of Hymenochaetales. There is a second rare British species of Cotylidia, C. undulata (B&K2/185), the type of the genus, also associated with mosses and also grouping near Rickenella. C. pannosa seems to have a different ecology and may be unrelated. The fifth British species is Stereopsis vitellina, affiliations still unknown, cream-coloured, usually on bare soil, described by Plowright in 1901 from Abernethy Forest, Inverness. It is
capable of forming weak rosettes but has much smaller spores than C. pannosa. It was not found again in Britain until 1999, again in Abernethy Forest, determined by Peter Orton and confirmed by Reid.
Fig.3. The only details provided by Sowerby of his Helvella pannosa.
References Eriksson, J. & Ryvarden, L. (1975). The Corticiaceae of North Europe Vol.3. Oslo, Fungiflora. lng, B. (1993). Towards a Red List of Endangered European Macrofungi. In Fungi of Europe: Investigation, Recording and Conservation. pp 231-237. Royal Botanic Gardens, Kew. Overall, A. & Mottram, K. (2006). Podoscypha multizonata - Zoned Rosette. Field Mycol. 7(3): 82-84. Reid, D.A. (1965). A Monograph of the Stipitate Stereoid Fungi. Nova Hedwigia Beiheft 18. 382pp. Sowerby, J. (1799). Coloured Figures of English Fungi or Mushrooms, Vol.2.
Fig.2. Helvella pannosa, plate of the type reproduced (with kind permission from Botanic Gardens, Kew) from James Coloured Figures of English Fungi Vol.2 (1799).
collection, the Royal Sowerby’s Plate 155
113