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Gloeoporus dichrous in Southern England
Field Mycology Volume 5(2), April 2004
GLOEOPORUS DICHROUS in southern England Martyn Ainsworth 53 Elm Road, Windsor, Berkshire SL4 3NB
BMS database records, reference material and British distribution In November 2003, the BMSFRD held ten records of Gloeoporus dichrous, nine of which were from three Scottish vice counties (VC 92, 95 and 96). Eight of the Scottish records date from the period 1963 to 1965 and Betula was the only associated tree species recorded (for three of the records). Following a gap of 33 years, the remaining Scottish record was made in 1998 and again the fungus was on Betula and in VC 92. The first English record added to the database was of a specimen collected from a small fallen Quercus robur branch lying in the litter of Windsor Great Park, Berkshire (VC 22) on 3 February 2001. There are only three British collections held at Kew, all of which correspond to BMSFRD records. Plotting the known distribution of G. dichrous by manually shading the vice county map associated with the BMSFRD produced the intriguing map shown in Fig. 1.
be noted in passing that the figures (but not the captions) accompanying their descriptions of G. dichrous and G. taxicola are transposed: G. dichrous has clamped septa whereas G. taxicola has simple septa. Hansen & Knudsen (1997) key out species of Gloeoporus alongside those of Meruliopsis (eg. Meruliopsis (Byssomerulius) corium) but maintain that uncertainty exists whether basidia are formed continuously over the dissepiments in all the species. Hence the two genera were retained, albeit seemingly frozen on the brink of synonymy. There are photographs and descriptions in Ryman & Holmåsen (1984), Breitenbach & Kränzlin (1986), on a commercially-available CD (Niemelä & Meike, 1999) and in a recent Finnish magazine (Niemelä, 2003). Recent Windsor records My surprise at the lack of English records turned to curiosity as further sightings were made on ten oaks from a series of woodlands, all with public access, within a single 10 km grid square. Specimens examined to date were all from small diameter Quercus robur branches within Windsor Great Park (Berkshire, VC 22) and collection details were as follows (the most recent was collected by E.E. Green and the others by A.M. Ainsworth): Stag Meadow area (SU 9575), on fallen branch in litter, 3 Feb. 2001 (fresh basidiocarps seen again on this branch 2 Sep. 2001); Queen Mary’s Plantation (SU 9575), on fallen branch in litter, 17 Nov. 2002; Swan Pond area (SU 9574), on fallen branch in litter, 21 May 2003; Cranbourne (SU 9573), on fallen branch in grass, 29 Mar. 2002 and on attached dead lower branch of nearby young oak, 7 Jul 2002; Prince of Wales Pond area (SU 9673), on fallen branch in grass, 25 Aug. 2002 and on attached dead lower branch of nearby young
G. dichrous in the popular literature That this is a fungus of uncertain affinity is amply demonstrated by the presence of three generic names among the ten databased records, ie. Gloeoporus dichrous, Bjerkandera dichroa and Caloporus dichrous. Ryvarden & Gilbertson (1993) included the two British species of Gloeoporus among the European polypores on the basis of their poroid basidiocarp form but recognised that the genus is probably more closely related to non-poroid taxa. More specifically, they noted that the development of basidia over the dissepiments (pore edges), as seen in Gloeoporus, is a character associated with species forming wrinkled basidiocarps in such genera as Phlebia and Byssomerulius. Furthermore, they acknowledged the difficulty of delimiting Byssomerulius and Gloeoporus. It should 45
Field Mycology Volume 5(2), April 2004
Fig. 1. Gloeoporus dichrous: known British distribution by vice county.
oak, 30 Jan. 2003; Bears Rails area (SU 9773), on fallen twig in litter, 2 Nov. 2002 and on a fallen branch from another tree, 11 Dec. 2003; Bishopsgate area (SU 9772), on fallen branch in grass, 15 Aug. 2003. Field characters The fungus forms patches of resupinate basidiocarps when fruiting directly beneath fallen or dead attached branches and, when fruiting on more vertical substrata, these are extended to form tiers of pliable brackets. The upper surface is white and hairy becom-
ing felt-like and greening due to the presence of algae (Fig. 2). Unfortunately this can give the initial impression of old bleached Bjerkandera or Stereum brackets, thus curtailing further examination. Young basidiocarps form a shallow gelatinous pore layer which is initially yellowish but soon develops pinkish tints (Fig. 3). The irregularly-shaped pores become more brownish as the basidiocarp matures and contrast strongly with the white sterile margin and upper surface. This contrast is accentuated further by the frequent presence of surrounding sterile white mycelial cushions (Fig. 4). Fully mature pore surfaces develop a purplish grey tint (Fig. 5), but retain their gelatinous consistency and can be scraped off with a finger nail. Ecology of G. dichrous In Berkshire, fresh basidiocarps of this species have been found in almost every month of the year. This, together with their location on oak twigs and small diameter branches might suggest a relatively desiccation-tolerant fruiting strategy. However it should be noted that basidiocarps were usually found by locating the dampest microhabitats associated with potential substrata. For example, fallen wood seemed most productive when surrounded by good litter or grass cover ensuring a slightly more humid microclimate and light-suppressed attached lower young branches seemed best when the oaks were open-grown but in groups, again creating a slightly more humid microclimate. Steccherinum ochraceum, or possibly the very similar S. bourdotii (A. Henrici pers. comm.) was noteworthy in its co-occurrence with G. dichrous on at least three trees bearing the examined specimens and basidiocarps were often in
Fig. 2. Felt-like upper surface of brackets with associated algae (May, Swan Pond).
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Field Mycology Volume 5(2), April 2004
Fig. 3. Young basidiocarp viewed from below showing gelatinous pores (February, Stag Meadow). Fig. 4. Maturing basidiocarp with surrounding cushions of white sterile mycelium (Sept., Prince of Wales Pond). Fig. 5. Fully mature basidiocarp showing purplish pore surface (May, Swan Pond). All photographs © Martyn Ainsworth.
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Field Mycology Volume 5(2), April 2004 close contact. Confusingly, the basidiocarps of all these species can be almost indistinguishable when viewed from above. The identity of associated Steccherinum basidiocarps was further investigated by revisiting the Cranbourne site and searching in a slightly different area on 4 January 2004. This revealed four further Q. robur branches (from different trees) bearing pileate basidiocarps of Steccherinum sp. near to those of G. dichrous. Measurements taken from spore prints deposited by all four Steccherinum samples confirmed that they were all of S. ochraceum, despite some basidiocarps having tiers of pilei and relatively robust spines (thought to be more usual in S. bourdotii). Dichomitus campestris, another unusual resupinate poroid, was also found in similar oak communities in the same woodlands as G. dichrous but, at the time of writing, they have not been found fruiting on the same branch. G. dichrous is widespread throughout the world and has been recorded on various broadleaved trees, a few conifers and dead basidiocarps of polypores. In northern Europe it is found predominantly on Betula (cf. Scottish records) and often fruits on wood occupied by Inonotus obliquus, suggesting it may secondarily capture territory from the pioneer community (see: Ryvarden & Gilbertson, 1993; Niemelä, 2003). Indeed Niemelä, Renvall & Penttilä (1995) referred to observations linking the two species which date back to the 1950s and regarded it as probably one of the first polypores to be suspected of having a relationship with a predecessor species. Clearly the ecology of its interactions within suppressed and naturally pruned branches of lowland English oaks requires further investigation.
Records required The strikingly two-toned basidiocarps of this fungus have now become a familiar sight within a single 10 km square of Berkshire, raising obvious questions about its true distribution in Britain. I have not systematically searched for this species elsewhere and hope that by publishing these photographs and drawing attention to its presence, we may begin to gain a clearer picture of its distribution, ecology and conservation status. Acknowledgements Thanks to the Crown Estate, Windsor, for a collection permit, to Ted Green for sending material he collected, to Alick Henrici for checking the Kew material and supplying details of S. bourdotii and to Paul Kirk for access to BMSFRD records of G. dichrous. References Breitenbach, J. & Kränzlin, F. (1986). Fungi of SwitzerlandVolume 2 Non-gilled fungi. Mykologia, Lucerne. Hansen, L. & Knudsen, H. eds. (1997). Nordic MacromycetesVol. 3. Nordsvamp, Copenhagen. Niemelä,T. (2003). Kääpien lumoava perikunta. Suomen Luonto 11/2003: 4-11. Niemelä,T. & Meike, J. (1999). CD Guide to t he Polypores of Finland. Finnish Museum of Natural History, Helsinki. Niemelä,T., Renvall, P. & Penttilä, R. (1995). Interactions of fungi at late stages of wood decomposition. Ann. Bot. Fennici 32: 141152. Ryman, S. & Holmåsen, I. (1984). Svampar. Interpublishing, Stockholm. Ryvarden, L. & Gilbertson, R.L. (1993). European Polypores. Fungiflora, Oslo.
Footnote pertaining to Oak Polypore article on p. 43 Permits needed for Schedule 8 species: Oak Polypore (Piptoporus quercinus) is one of 34 fungi legally protected from collection even for scientific purposes by Schedule 8 of the Wildlife and Countryside Act 1981.The Act only applies to England, Scotland and Wales not Northern Ireland, the Republic of Ireland, the Channel Islands or the Isle of Man. Only four are non-lichenized fungi. These are: Hericium erinaceum (Bearded Tooth); Buglossoporus pulvinus = Piptoporus quercinus (Oak Polypore); Boletus regius (Royal Bolete) and Battarraea phalloides (Sandy Stiltball). Licences for collection of these species should be obtained by application to the appropriate authority (English Nature, Scottish Natural Heritage or Countryside Council for Wales).
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GLOEOPORUS DICHROUS in southern England Martyn Ainsworth 53 Elm Road, Windsor, Berkshire SL4 3NB
BMS database records, reference material and British distribution In November 2003, the BMSFRD held ten records of Gloeoporus dichrous, nine of which were from three Scottish vice counties (VC 92, 95 and 96). Eight of the Scottish records date from the period 1963 to 1965 and Betula was the only associated tree species recorded (for three of the records). Following a gap of 33 years, the remaining Scottish record was made in 1998 and again the fungus was on Betula and in VC 92. The first English record added to the database was of a specimen collected from a small fallen Quercus robur branch lying in the litter of Windsor Great Park, Berkshire (VC 22) on 3 February 2001. There are only three British collections held at Kew, all of which correspond to BMSFRD records. Plotting the known distribution of G. dichrous by manually shading the vice county map associated with the BMSFRD produced the intriguing map shown in Fig. 1.
be noted in passing that the figures (but not the captions) accompanying their descriptions of G. dichrous and G. taxicola are transposed: G. dichrous has clamped septa whereas G. taxicola has simple septa. Hansen & Knudsen (1997) key out species of Gloeoporus alongside those of Meruliopsis (eg. Meruliopsis (Byssomerulius) corium) but maintain that uncertainty exists whether basidia are formed continuously over the dissepiments in all the species. Hence the two genera were retained, albeit seemingly frozen on the brink of synonymy. There are photographs and descriptions in Ryman & Holmåsen (1984), Breitenbach & Kränzlin (1986), on a commercially-available CD (Niemelä & Meike, 1999) and in a recent Finnish magazine (Niemelä, 2003). Recent Windsor records My surprise at the lack of English records turned to curiosity as further sightings were made on ten oaks from a series of woodlands, all with public access, within a single 10 km grid square. Specimens examined to date were all from small diameter Quercus robur branches within Windsor Great Park (Berkshire, VC 22) and collection details were as follows (the most recent was collected by E.E. Green and the others by A.M. Ainsworth): Stag Meadow area (SU 9575), on fallen branch in litter, 3 Feb. 2001 (fresh basidiocarps seen again on this branch 2 Sep. 2001); Queen Mary’s Plantation (SU 9575), on fallen branch in litter, 17 Nov. 2002; Swan Pond area (SU 9574), on fallen branch in litter, 21 May 2003; Cranbourne (SU 9573), on fallen branch in grass, 29 Mar. 2002 and on attached dead lower branch of nearby young oak, 7 Jul 2002; Prince of Wales Pond area (SU 9673), on fallen branch in grass, 25 Aug. 2002 and on attached dead lower branch of nearby young
G. dichrous in the popular literature That this is a fungus of uncertain affinity is amply demonstrated by the presence of three generic names among the ten databased records, ie. Gloeoporus dichrous, Bjerkandera dichroa and Caloporus dichrous. Ryvarden & Gilbertson (1993) included the two British species of Gloeoporus among the European polypores on the basis of their poroid basidiocarp form but recognised that the genus is probably more closely related to non-poroid taxa. More specifically, they noted that the development of basidia over the dissepiments (pore edges), as seen in Gloeoporus, is a character associated with species forming wrinkled basidiocarps in such genera as Phlebia and Byssomerulius. Furthermore, they acknowledged the difficulty of delimiting Byssomerulius and Gloeoporus. It should 45
Field Mycology Volume 5(2), April 2004
Fig. 1. Gloeoporus dichrous: known British distribution by vice county.
oak, 30 Jan. 2003; Bears Rails area (SU 9773), on fallen twig in litter, 2 Nov. 2002 and on a fallen branch from another tree, 11 Dec. 2003; Bishopsgate area (SU 9772), on fallen branch in grass, 15 Aug. 2003. Field characters The fungus forms patches of resupinate basidiocarps when fruiting directly beneath fallen or dead attached branches and, when fruiting on more vertical substrata, these are extended to form tiers of pliable brackets. The upper surface is white and hairy becom-
ing felt-like and greening due to the presence of algae (Fig. 2). Unfortunately this can give the initial impression of old bleached Bjerkandera or Stereum brackets, thus curtailing further examination. Young basidiocarps form a shallow gelatinous pore layer which is initially yellowish but soon develops pinkish tints (Fig. 3). The irregularly-shaped pores become more brownish as the basidiocarp matures and contrast strongly with the white sterile margin and upper surface. This contrast is accentuated further by the frequent presence of surrounding sterile white mycelial cushions (Fig. 4). Fully mature pore surfaces develop a purplish grey tint (Fig. 5), but retain their gelatinous consistency and can be scraped off with a finger nail. Ecology of G. dichrous In Berkshire, fresh basidiocarps of this species have been found in almost every month of the year. This, together with their location on oak twigs and small diameter branches might suggest a relatively desiccation-tolerant fruiting strategy. However it should be noted that basidiocarps were usually found by locating the dampest microhabitats associated with potential substrata. For example, fallen wood seemed most productive when surrounded by good litter or grass cover ensuring a slightly more humid microclimate and light-suppressed attached lower young branches seemed best when the oaks were open-grown but in groups, again creating a slightly more humid microclimate. Steccherinum ochraceum, or possibly the very similar S. bourdotii (A. Henrici pers. comm.) was noteworthy in its co-occurrence with G. dichrous on at least three trees bearing the examined specimens and basidiocarps were often in
Fig. 2. Felt-like upper surface of brackets with associated algae (May, Swan Pond).
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Field Mycology Volume 5(2), April 2004
Fig. 3. Young basidiocarp viewed from below showing gelatinous pores (February, Stag Meadow). Fig. 4. Maturing basidiocarp with surrounding cushions of white sterile mycelium (Sept., Prince of Wales Pond). Fig. 5. Fully mature basidiocarp showing purplish pore surface (May, Swan Pond). All photographs © Martyn Ainsworth.
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Field Mycology Volume 5(2), April 2004 close contact. Confusingly, the basidiocarps of all these species can be almost indistinguishable when viewed from above. The identity of associated Steccherinum basidiocarps was further investigated by revisiting the Cranbourne site and searching in a slightly different area on 4 January 2004. This revealed four further Q. robur branches (from different trees) bearing pileate basidiocarps of Steccherinum sp. near to those of G. dichrous. Measurements taken from spore prints deposited by all four Steccherinum samples confirmed that they were all of S. ochraceum, despite some basidiocarps having tiers of pilei and relatively robust spines (thought to be more usual in S. bourdotii). Dichomitus campestris, another unusual resupinate poroid, was also found in similar oak communities in the same woodlands as G. dichrous but, at the time of writing, they have not been found fruiting on the same branch. G. dichrous is widespread throughout the world and has been recorded on various broadleaved trees, a few conifers and dead basidiocarps of polypores. In northern Europe it is found predominantly on Betula (cf. Scottish records) and often fruits on wood occupied by Inonotus obliquus, suggesting it may secondarily capture territory from the pioneer community (see: Ryvarden & Gilbertson, 1993; Niemelä, 2003). Indeed Niemelä, Renvall & Penttilä (1995) referred to observations linking the two species which date back to the 1950s and regarded it as probably one of the first polypores to be suspected of having a relationship with a predecessor species. Clearly the ecology of its interactions within suppressed and naturally pruned branches of lowland English oaks requires further investigation.
Records required The strikingly two-toned basidiocarps of this fungus have now become a familiar sight within a single 10 km square of Berkshire, raising obvious questions about its true distribution in Britain. I have not systematically searched for this species elsewhere and hope that by publishing these photographs and drawing attention to its presence, we may begin to gain a clearer picture of its distribution, ecology and conservation status. Acknowledgements Thanks to the Crown Estate, Windsor, for a collection permit, to Ted Green for sending material he collected, to Alick Henrici for checking the Kew material and supplying details of S. bourdotii and to Paul Kirk for access to BMSFRD records of G. dichrous. References Breitenbach, J. & Kränzlin, F. (1986). Fungi of SwitzerlandVolume 2 Non-gilled fungi. Mykologia, Lucerne. Hansen, L. & Knudsen, H. eds. (1997). Nordic MacromycetesVol. 3. Nordsvamp, Copenhagen. Niemelä,T. (2003). Kääpien lumoava perikunta. Suomen Luonto 11/2003: 4-11. Niemelä,T. & Meike, J. (1999). CD Guide to t he Polypores of Finland. Finnish Museum of Natural History, Helsinki. Niemelä,T., Renvall, P. & Penttilä, R. (1995). Interactions of fungi at late stages of wood decomposition. Ann. Bot. Fennici 32: 141152. Ryman, S. & Holmåsen, I. (1984). Svampar. Interpublishing, Stockholm. Ryvarden, L. & Gilbertson, R.L. (1993). European Polypores. Fungiflora, Oslo.
Footnote pertaining to Oak Polypore article on p. 43 Permits needed for Schedule 8 species: Oak Polypore (Piptoporus quercinus) is one of 34 fungi legally protected from collection even for scientific purposes by Schedule 8 of the Wildlife and Countryside Act 1981.The Act only applies to England, Scotland and Wales not Northern Ireland, the Republic of Ireland, the Channel Islands or the Isle of Man. Only four are non-lichenized fungi. These are: Hericium erinaceum (Bearded Tooth); Buglossoporus pulvinus = Piptoporus quercinus (Oak Polypore); Boletus regius (Royal Bolete) and Battarraea phalloides (Sandy Stiltball). Licences for collection of these species should be obtained by application to the appropriate authority (English Nature, Scottish Natural Heritage or Countryside Council for Wales).
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