Russula nobilis
Description
Russula nobilis is a toxic, brittle, red-capped mushroom. It is only found in beech woodland and help beech trees take up nutrients from the soil. The gills are white and crumbly and the stipe is white and brittle. It is toxic, though not usually deadly, and when chewed tastes hot and acrid.
This mushroom is also known by the binomial name of Russula mairei. The Russula family split from other mushrooms, evolutionarily, many years ago and have round cells instead of most other mushrooms which have elongated cells, this gives Russulas the common name Brittlegills as the cells make the mushroom brittle.
Common names: Beechwood Sickener.
Mushroom Identification
Cap
Caps of the Beechwood Sickener are 3 to 9cm dia., smooth, non-striate and bright red or pink (very occasionally almost completely white). The cap of this species generally remains convex with at most only a shallow central depression, whereas caps of the (conifer associated) Sickener Russula emetica become funnel-shaped when fully mature.
Slightly sticky when wet, the cap surface dries to a matt finish.
Flesh
Red or pink immediately beneath the cuticle; elsewhere the flesh is white.
Gills
White, sometimes with a greenish tinge, the adnexed, crowded gills of the Beechwood Sickener Russula nobilis are very brittle indeed and easily crumble if they are handled.
Stem
Stems of Russula nobilis are 10 to 15mm in diameter and 20 to 40mm tall, the white stems are smooth and slightly clavate. The stem flesh is white, and as with other brittlegill mushrooms, there is no stem ring.
Spores
Ovoid, 7-8 x 6-6.5µm; with warts up to 0.5µm tall, joined by narrow connectives in a nearly complete reticulum.
Spore Print
White.
Odor and Taste
The faint odor of coconut in young specimens; tastes rapidly very hot and acrid.
Habitat & Ecological Role
Under Beech trees, with which it is ectomycorrhizal.
Similar Species
Russula emetica is found under conifers; its cap becomes depressed when fully mature and the cap cuticle peels more readily. It is just as poisonous as Russula nobilis and so both should be avoided when gathering mushrooms for food.
History
Described in 1920 by Czech mycologist Josef Velenovský (1858 - 1949) , who gave it the name Russula nobilis, this brittlegill retains that scientific name to the present time.
Russula nobilis has several synonyms including Russula mairei Singer, Russula fageticola Melzer ex S. Lundell, and Russula mairei var. fageticola Romagn.
Russula, the generic name, means red or reddish, and indeed many of the brittlegills have red caps.
The specific epithet nobilis means noble, distinct or famous - take your pick. This species was until recently better known as Russula mairei, and that specific epithet, conferred by Rolf Singer, honored French botanist-mycologist René Charles Joseph Ernest Maire (1878 - 1949).
Photo sources:
Photo 1 - Author: cmy610 (CC BY-SA 3.0)
Photo 2 - Author: Holger Krisp (CC BY 3.0)
Photo 3 - Author: Len Worthington (CC BY-SA 2.0)
Photo 4 - Author: Ragnar1904 (CC BY-SA 4.0)
