Fungal Portraits No. 51: Russula plumbeobrunnea

Fungal Portraits No. 51: Russula plumbeobrunnea

Vol 13 (3) FUNGAL PORTRAITS No. 51: Russula plumbeobrunnea Geoffrey Kibby Fig. 1. Russula plumbeobrunnea. Growing close to Quercus sp. in Kew Garden...

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Vol 13 (3)

FUNGAL PORTRAITS No. 51: Russula plumbeobrunnea Geoffrey Kibby

Fig. 1. Russula plumbeobrunnea. Growing close to Quercus sp. in Kew Gardens, September, 2011. Photo © Geoffrey Kibby.

ussula parazurea is a familiar species recorded on many fungus forays throughout the season. But it seems a surprising amount of variation in colour, cap texture, spore ornamentation etc have been absorbed into our concept of the species. It is a natural human tendency to try and make things ‘fit’ a description, a tendency to which I plead as guilty as the next person. But I was never very happy with the variation I was trying to accept. It was only when a paper was published by W. Jurkeit, W. Schössler, B. Grouwinkel & J. Albers in 2010 describing a new species of greyish Russula from Germany that I and several other mycologists around Europe (judging by various on-line mycological forums) said “Ah! So that is what we have been finding...”. Russula plumbeobrunnea Jurkeit & Schössler is a species closely related to R. parazurea, both being in the subsection Griseinae, characterised

by cap colours ranging from grey through bluish, greenish or lilac to cream; spores white to cream (rarely pale ochre), low sporal ornamentation; clavate to fusiform pileocystidia and mild taste. In order to understand the differences between this new species and R. parazurea one must first have a clearer concept of the latter.

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doi:10.1016/j.fldmyc.2012.06.003

R. parazurea Jul. Schäff. The original description of this species by Julius Schäffer describes it (translated from the Latin) as: “...pileus typically slate green, dry, densely pruinose, opaque....spores pale cream.....dermatocystidia clavate to fusoid”. Fruitbodies matching this description closely are found quite commonly in both conifer and broadleaf woods and when young and fresh do indeed have beautifully pruinose caps with bluish grey to greenish grey colours (Fig. 2). The spores of R. parazurea should be 6.0–8.0 x 5.0–7.0 µm, with low warts up

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Fig. 2. Russula parazurea showing the beautifully pruinose caps. Photograph © L. Stridvall.

centre and sometimes paler, more pinkish grey at the margin. It is never pruinose, being instead rather smooth and shiny (Fig. 1). Other features are: gills white to pale cream, brittle; taste mild to slightly acrid in very young gills; stem short, stout, white to slightly brown with age; spores 5.5–8.5 x 4.7–6.3 µm, warts to 0.5 high, with a partial or poorly connected reticulum; pileocystidia narrowly fusiform to very broadly clavate, sometimes with swollen ends; cuticular hyphae forming chains of rather short, broad and swollen cells, apical cells short, swollen or pointed (Fig. 3). It appears to be frequent in the south of England with Quercus. Since its original publication the species has also been formally recorded from the Netherlands (Wisman, 2011).

Fig. 3. Left: Russula plumbeobrunnea Right: Russula parazurea. Cystidia are stippled.

to 0.5 µm high, connected by a more or less complete reticulum. The pileocystidia are unicellular, narrowly fusiform to moderately clavate. The cuticular hyphae are narrow and cylindric, with the apical cell long and tapering (Fig. 3).

References Jurkeit, W., Schössler, W., Grauwinkle, B. & Albers, J. (2010). Russula -Forschung in Mitteleuropa I. Zwei neue Täublinge aus Deutschland. Zeitsch. Mykol. 76(1): 3–26. Wisman, J. (2011). Russula plumbeobrunnea tot nu toe steeds verward met Russula parazurea. Coolia 54(3).

R. plumbeobrunnea Jurkeit & Schössler The pileus of this species is, as the name suggests, greyish brown, often browner at the

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