Russula gracillima

Description

Russula gracillima is a member of the genus Russula. It is a small, pale, long-stemmed brittlegill associated mainly with birch and is occasional in Europe, Asia, and North America. It appears occasionally in summer to late autumn, usually growing in small groups with birch, or sometimes willow in damp places.

Common names: Slender Brittlegill.

Mushroom Identification

1. Cap

   2 to 5cm in diameter, the fragile caps soon flatten and often with slightly depressed centers but retailing a downturned margin. The silky-smooth cap is slightly viscid when wet; its cuticle peels to between 1/2 and 3/4 to the center. Mature specimens often develop a furrowed and somewhat lumpy margin. (The technical term for a furrowed margin is 'sulcate'.) Cap color varies from pale violet through rose or flesh colored to salmon pink, with pale greenish or olivaceous (occasionally dark grey) tinges in the central region. As with many of the reddish brittlegills, much of the cap color may be washed off in prolonged wet weather.

2. Flesh

   The flesh of this brittlegill turns yellowish-pink with FeSO4 (iron salts).

3. Gills

   Adnexed, broad and moderately spaced, the gills are pale creams, brittle, and very fragile.

4. Stem

   Cylindrical but usually narrowing towards the apex and occasionally with a slightly clavate base; slender, 3 to 7cm tall (taller than the cap diameter, hence the common name), the brittle stems are white often flushed slightly with pale pink, becoming greyer with age. There is no stem ring.

5. Spores

   Ovoid; 7-8.5 x 5-6.5µm; ornamented with isolated warts (not joined by ridges) up to 1 µm tall.

6. Spore Print

   Pale to mid cream.

7. Odor and Taste

   No distinctive odor; slightly to very hot taste.

8. Habitat & Ecological Role

   In damp broadleaf woodland, often with birches. In common with other members of the Russulaceae, Russula gracillima is an ectomycorrhizal mushroom.

Look-Alikes

1. Russula rosea

   A bright pink brittlegill with a much larger cap; it grown with broadleaf trees but also occasionally with conifers.

2. Russula fragilis

   Similar but produces a white spore print; its flesh tastes extremely hot.

3. Russula betularum

   Which is frequently found near birch trees, and although usually paler can be mistaken for washed out specimens of R. racillima.

History

When German mycologist Julius Schäffer (1882 - 1944) described this brittlegill in 1931 he gave it the binomial scientific name Russula gracillima; this is still the generally-accepted scientific name.

A very similar brittlegill is found in North America and has the scientific name Russula gracilis Burlingham. American mycologist Gertrude Simmons Burlingham (1872–1952) described this species in 1915, and if DNA sequencing shows it to be the same species as Russula gracillima Jul. Schäff., then the name of the European species would have to change to Russula gracillis, as the earlier description takes precedence.

Russula, the generic name, means red or reddish, and indeed many of the brittlegills have red caps.

The specific epithet gracillima comes from the Latin adjective gracillis meaning slender or slim.

Photo sources:

Photo 1 - Author: federicocalledda (CC BY-NC 4.0)

Photo 2 - Author: juhakinnunen (CC BY-NC 4.0)