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Cantharellus romagnesianus new to Britain
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Cantharellus romagnesianus new to Britain ! #&'&##!B
T
he river Tamar forms a natural boundary between the counties of Devon and Cornwall and in the lower reaches the steep river cliffs are frequently wooded. Greenscombe wood near Luckett, on the Cornish side constitutes one such area. It is part conifer plantation, part replanted ancient woodland. There has been intense human activity here throughout history, from Iron Age forts, silver and copper mining and market gardening. Despite this disturbance the area now has a rich flora and fauna and is one of the few breeding grounds of the rare Heath Fritillary (Melitaea athalia). Cornwall Fungus Recording Group visited in the spring and autumn of 2017. The autumn finds included a good number of Phellodon confluens on a streamside bank. There were large numbers of Cantharellus cibarius on the upper slopes of the mixed woodland. Richard Vulliamy, previously a warden for the wood, collected a specimen from the banks of the Iron Age fort where the predominant tree species is sessile oak (Quercus petraea) with some birch. He felt it was of an unusual form of C. cibarius, as it was a darker yellow, small and gracile, yet had the characteristic wrinkled hymenium (Fig. 1). It certainly warranted closer examination.
(Kibby, 2017) has an updated, comprehensive section on the family Cantharellaceae which includes Cantharellus and Craterellus, the latter having a similar form but hollow stems. The illustration and description there of Cantharellus romagnesianus most closely fitted this specimen. It was noted that it had not yet been recorded in the UK, but Kibby predicted it might well be found in British Atlantic woodlands. On the basis of this, assistance was sought from Martyn Ainsworth at Kew. There Kare Liimatainen undertook DNA sequencing on the specimen and a match with C. romagnesianus was established. The specimen was retained in the fungarium at Kew as K(M)236735. Cantharellus romagnesianus (Eyssartier & Buyck, 1999) is known from Italy, France, Portugal and the NW of Spain and is found with a wide variety of coniferous and broadleaved trees. The key features of C. romagnesianus are its small stature, an orange-yellow cap colour and thin cap flesh. It has a slender, cylindrical stipe, the base of which may be a darker orange-red, or bruise darker on handling. Note that bruising also occurs in C. pallens and C. ferruginascens. The other small, gracile Cantharellus is C. friesii. This however has a pinkish cap and stipe which does not bruise or darken towards the base and is found predominantly with Fagus. There are few definitive microscopic features with which to separate the species of this genus. The two smallest species, C. friesii and C. romagnesianus, have the largest spores. However spore size and shape is variable in C. romagnesianus, spores may or may not be centrally constricted and their size range is large: 8–12 x 4–6.5 µm. The basidia are mainly five spored and 70–86 x 9–12 µm. Recently, a phylogenetic study of Cantharellus has been undertaken to determine the species currently known in Europe, there being no less than 30 species names in the literature.
Description Cap orange-yellow, smooth, 18 mm diameter, convex, lobed and thin fleshed. Hymenium wrinkled, giving the appearance of well-formed, forking ‘gills’, just slightly decurrent and slightly paler than the cap. Stipe 25 x 3 mm cylindrical, terete, concolorous with the cap but darkening to light brown at the base. Spore print orangeyellow. Spores ellipsoidal 8–10 x 4–5 µm, with a distinct apiculus and no germ pore. Fortuitously, Geoffrey Kibby’s beautifully illustrated new volume Mushrooms and Toadstools of Britain and Europe Volume 1
B! #&&##!@/! $
doi:10.1016/j.fldmyc.2018.10.004
884
D$ 'F'GEH (Olariaga et al. 2017). This study identified only eight genetically distinct species, five of which are already recorded in Britain. C. romagnesianus will make the sixth. This excellent paper discusses morphological features which will aid identification of species within the genus, such as tree associates, habitus, cap and stipe colour, presence of pruinosity on the cap surface and colour change on handling. However these characteristics can be variable or absent, but should be able to form the basis of identification, particularly if fresh young specimens are collected. Fruitbodies of this genus can be particularly enduring, so weathering can cause changes to the cap colour and pruinosity which may lead to misidentification. Albino forms can also occur in most species. Staining on handling is another useful morphological feature which can be affected by fruitbody age and dessication. One feature stressed is the thickness in microns of the wall of the upper pileipellis hyphae in 5% KOH. C. pallens 1–2 µm C. cibarius 1–1.5 µm C. ferruginascens 0.6–1.5 µm C. amethystinus 0.5–1.0 µm C. romagnesianus ≤0.8 µm C. friesii ≤ 0.5 µm
consideration. Kibby (2012) gave a key to British species that also covered Craterellus. He has kindly provided the following updated version of its Cantharellus component. With the prediction in Kibby (2017) now a reality, that C. romagnesianus might appear in Britain, it would be timely to look more carefully at chanterelles, particularly if under evergreen oaks, for his other predicted European species Cantharellus alborufescens. This looks more like C. cibarius but has a paler hymenium and stipe which bruises brown on handling, see the description in Kibby (2017) and the key below. The eighth European species C. roseofagetorum is known only from Georgia and is less likely to be found in Britain but is nevertheless included in the key for completeness. Key to European species of Cantharellus * * = not yet British 1. Cap with delicate lilac-lavender felty tomentum (often very faint); hymenium yellow, flesh bruising rust-yellow, occasional in Britain.................................C. amethysteus 1. Cap with white, yellow, orange or at most pinkish tones....................................................2 2. Cap usually not greater than 30 (-50) mm, thin-fleshed, stem up to 10 mm thick; hyphae of cap cuticle usually thin-walled ≤ 0.8 µm .....3
A key is provided taking all the above into
'' " "! ! "
" ' $ & "&I'#I&%'$!'!#I' % ''; !%I'D !'!"' Greenscombe Wood
near Luckett, Cornwall, autumn 2017.K(M)236735. Scale bar = 20 mm. Digital composition of two photos of the single specimen.
882
D$ 'F'GEH Acknowledgments Thanks go to Richard Vulliamy, Martyn Ainsworth, Kare Liimateinen, Geoffrey Kibby and Alick Henrici without whose assistance I would have been unable to write this article.
2. Cap up to 130 mm, fleshy, stem up to 20 mm thick; hyphae of cap cuticle usually ≥0.8 µm ..4 3. Cap pinkish orange to orange-red, hymenium pale pinkish orange; stem base concolorous, spores 9–12 x 5–6 (-7) µm, mostly with Fagus; uncommon in Britain .........................C. friesii 3. Cap orange-yellow to ochre-yellow, sometimes white, sometimes staining upon handling; stem base often red; under deciduous or coniferous trees, rare in Britain, confined to Atlantic woodlands?..........C. romagnesianus
References Eyssartier, G. & Buyck, B. (2000). Le genre Cantharellus en Europe. Nomenclature et taxonomie. Bull. Soc. Mycol. France 116(2): 91–137. Kibby, G. (2012). Fungal Portraits No 52 Chanterelles and their allies. Field Mycology 13 (4): 111–117. Kibby, G. (2017). Mushrooms and Toadstools of Britain and Europe Vol. 1. Privately published, available from most mushroom book dealers. Olariaga, I., et al. (2017). Cantharellus (Cantharellales, Basidiomycota) revisited in Europe through a multigene phylogeny. Fungal Diversity 83: 263–292.
4. Hymenium white or off-white when young, often remaining so near the cap margin; growing under deciduous trees .......................5 4. Hymenium yellow-ochre to orange-yellow when young, at least near the margin; growing with deciduous or coniferous trees ..................7 5. Typically associated with evergreen Quercus on calcareous soils; cap medium-sized to large, never with citrine yellow, green or brown shades ....................**C. alborufescens 5. Not associated with evergreen oaks; cap small to medium-sized, sometimes citrine-yellow or with green or brown shades.............................6 6. Cap with a white coating when young; pileus ochre-yellow when the white coating disappears; so far only known from eastern European Georgia under Fagus orientalis .......................................**C. roseofagetorum 6. Cap without a white coating, small to mediumsized, sometimes citrine yellow or with green or brown shades; rare in Britain ....................... ............................................C. ferruginascens 7. Cap not or at most weakly covered with a whitish pruina; only weakly staining; hymenium uniformly ochre-yellow to orangeyellow, common throughout Britain ........................................................C. cibarius 7. Cap always partially to entirely with a white coat when young, this later disappearing in patches; hymenium usually having a distinctly brighter colour near the pileus margin, uncommon; found in southern England............ ..........................................................C. pallens
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Cantharellus romagnesianus new to Britain ! #&'&##!B
T
he river Tamar forms a natural boundary between the counties of Devon and Cornwall and in the lower reaches the steep river cliffs are frequently wooded. Greenscombe wood near Luckett, on the Cornish side constitutes one such area. It is part conifer plantation, part replanted ancient woodland. There has been intense human activity here throughout history, from Iron Age forts, silver and copper mining and market gardening. Despite this disturbance the area now has a rich flora and fauna and is one of the few breeding grounds of the rare Heath Fritillary (Melitaea athalia). Cornwall Fungus Recording Group visited in the spring and autumn of 2017. The autumn finds included a good number of Phellodon confluens on a streamside bank. There were large numbers of Cantharellus cibarius on the upper slopes of the mixed woodland. Richard Vulliamy, previously a warden for the wood, collected a specimen from the banks of the Iron Age fort where the predominant tree species is sessile oak (Quercus petraea) with some birch. He felt it was of an unusual form of C. cibarius, as it was a darker yellow, small and gracile, yet had the characteristic wrinkled hymenium (Fig. 1). It certainly warranted closer examination.
(Kibby, 2017) has an updated, comprehensive section on the family Cantharellaceae which includes Cantharellus and Craterellus, the latter having a similar form but hollow stems. The illustration and description there of Cantharellus romagnesianus most closely fitted this specimen. It was noted that it had not yet been recorded in the UK, but Kibby predicted it might well be found in British Atlantic woodlands. On the basis of this, assistance was sought from Martyn Ainsworth at Kew. There Kare Liimatainen undertook DNA sequencing on the specimen and a match with C. romagnesianus was established. The specimen was retained in the fungarium at Kew as K(M)236735. Cantharellus romagnesianus (Eyssartier & Buyck, 1999) is known from Italy, France, Portugal and the NW of Spain and is found with a wide variety of coniferous and broadleaved trees. The key features of C. romagnesianus are its small stature, an orange-yellow cap colour and thin cap flesh. It has a slender, cylindrical stipe, the base of which may be a darker orange-red, or bruise darker on handling. Note that bruising also occurs in C. pallens and C. ferruginascens. The other small, gracile Cantharellus is C. friesii. This however has a pinkish cap and stipe which does not bruise or darken towards the base and is found predominantly with Fagus. There are few definitive microscopic features with which to separate the species of this genus. The two smallest species, C. friesii and C. romagnesianus, have the largest spores. However spore size and shape is variable in C. romagnesianus, spores may or may not be centrally constricted and their size range is large: 8–12 x 4–6.5 µm. The basidia are mainly five spored and 70–86 x 9–12 µm. Recently, a phylogenetic study of Cantharellus has been undertaken to determine the species currently known in Europe, there being no less than 30 species names in the literature.
Description Cap orange-yellow, smooth, 18 mm diameter, convex, lobed and thin fleshed. Hymenium wrinkled, giving the appearance of well-formed, forking ‘gills’, just slightly decurrent and slightly paler than the cap. Stipe 25 x 3 mm cylindrical, terete, concolorous with the cap but darkening to light brown at the base. Spore print orangeyellow. Spores ellipsoidal 8–10 x 4–5 µm, with a distinct apiculus and no germ pore. Fortuitously, Geoffrey Kibby’s beautifully illustrated new volume Mushrooms and Toadstools of Britain and Europe Volume 1
B! #&&##!@/! $
doi:10.1016/j.fldmyc.2018.10.004
884
D$ 'F'GEH (Olariaga et al. 2017). This study identified only eight genetically distinct species, five of which are already recorded in Britain. C. romagnesianus will make the sixth. This excellent paper discusses morphological features which will aid identification of species within the genus, such as tree associates, habitus, cap and stipe colour, presence of pruinosity on the cap surface and colour change on handling. However these characteristics can be variable or absent, but should be able to form the basis of identification, particularly if fresh young specimens are collected. Fruitbodies of this genus can be particularly enduring, so weathering can cause changes to the cap colour and pruinosity which may lead to misidentification. Albino forms can also occur in most species. Staining on handling is another useful morphological feature which can be affected by fruitbody age and dessication. One feature stressed is the thickness in microns of the wall of the upper pileipellis hyphae in 5% KOH. C. pallens 1–2 µm C. cibarius 1–1.5 µm C. ferruginascens 0.6–1.5 µm C. amethystinus 0.5–1.0 µm C. romagnesianus ≤0.8 µm C. friesii ≤ 0.5 µm
consideration. Kibby (2012) gave a key to British species that also covered Craterellus. He has kindly provided the following updated version of its Cantharellus component. With the prediction in Kibby (2017) now a reality, that C. romagnesianus might appear in Britain, it would be timely to look more carefully at chanterelles, particularly if under evergreen oaks, for his other predicted European species Cantharellus alborufescens. This looks more like C. cibarius but has a paler hymenium and stipe which bruises brown on handling, see the description in Kibby (2017) and the key below. The eighth European species C. roseofagetorum is known only from Georgia and is less likely to be found in Britain but is nevertheless included in the key for completeness. Key to European species of Cantharellus * * = not yet British 1. Cap with delicate lilac-lavender felty tomentum (often very faint); hymenium yellow, flesh bruising rust-yellow, occasional in Britain.................................C. amethysteus 1. Cap with white, yellow, orange or at most pinkish tones....................................................2 2. Cap usually not greater than 30 (-50) mm, thin-fleshed, stem up to 10 mm thick; hyphae of cap cuticle usually thin-walled ≤ 0.8 µm .....3
A key is provided taking all the above into
'' " "! ! "
" ' $ & "&I'#I&%'$!'!#I' % ''; !%I'D !'!"' Greenscombe Wood
near Luckett, Cornwall, autumn 2017.K(M)236735. Scale bar = 20 mm. Digital composition of two photos of the single specimen.
882
D$ 'F'GEH Acknowledgments Thanks go to Richard Vulliamy, Martyn Ainsworth, Kare Liimateinen, Geoffrey Kibby and Alick Henrici without whose assistance I would have been unable to write this article.
2. Cap up to 130 mm, fleshy, stem up to 20 mm thick; hyphae of cap cuticle usually ≥0.8 µm ..4 3. Cap pinkish orange to orange-red, hymenium pale pinkish orange; stem base concolorous, spores 9–12 x 5–6 (-7) µm, mostly with Fagus; uncommon in Britain .........................C. friesii 3. Cap orange-yellow to ochre-yellow, sometimes white, sometimes staining upon handling; stem base often red; under deciduous or coniferous trees, rare in Britain, confined to Atlantic woodlands?..........C. romagnesianus
References Eyssartier, G. & Buyck, B. (2000). Le genre Cantharellus en Europe. Nomenclature et taxonomie. Bull. Soc. Mycol. France 116(2): 91–137. Kibby, G. (2012). Fungal Portraits No 52 Chanterelles and their allies. Field Mycology 13 (4): 111–117. Kibby, G. (2017). Mushrooms and Toadstools of Britain and Europe Vol. 1. Privately published, available from most mushroom book dealers. Olariaga, I., et al. (2017). Cantharellus (Cantharellales, Basidiomycota) revisited in Europe through a multigene phylogeny. Fungal Diversity 83: 263–292.
4. Hymenium white or off-white when young, often remaining so near the cap margin; growing under deciduous trees .......................5 4. Hymenium yellow-ochre to orange-yellow when young, at least near the margin; growing with deciduous or coniferous trees ..................7 5. Typically associated with evergreen Quercus on calcareous soils; cap medium-sized to large, never with citrine yellow, green or brown shades ....................**C. alborufescens 5. Not associated with evergreen oaks; cap small to medium-sized, sometimes citrine-yellow or with green or brown shades.............................6 6. Cap with a white coating when young; pileus ochre-yellow when the white coating disappears; so far only known from eastern European Georgia under Fagus orientalis .......................................**C. roseofagetorum 6. Cap without a white coating, small to mediumsized, sometimes citrine yellow or with green or brown shades; rare in Britain ....................... ............................................C. ferruginascens 7. Cap not or at most weakly covered with a whitish pruina; only weakly staining; hymenium uniformly ochre-yellow to orangeyellow, common throughout Britain ........................................................C. cibarius 7. Cap always partially to entirely with a white coat when young, this later disappearing in patches; hymenium usually having a distinctly brighter colour near the pileus margin, uncommon; found in southern England............ ..........................................................C. pallens
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