Russula aeruginea

Description

Russula aeruginea is recognized by a green to grayish-green cap that fades to yellowish-green in age, never developing purple or vinaceous shades, a white stipe, mild taste, and pale yellow spores. Habitat solitary to gregarious in the soil in coastal conifer and montane pine-fir forests; common, fruiting in fall in the Sierra Nevada and Cascade Ranges, seldom along the coast.

Common names: Grass-green Russula, Tacky Green Russula, Green Russula, Grönkremla (Sweden), Zilzaļā bērzlape (Austria).

Mushroom Identification

1. Ecology

   Mycorrhizal with hardwoods or conifers; growing alone, scattered, or gregariously; summer and fall; widely distributed in North America.

2. Cap

   5-9 cm; convex when young, becoming broadly convex to flat with a shallow depression; dry or slightly moist; smooth, or minutely velvety over the center; grayish-green to yellowish-green; the margin often lined by maturity; the skin peeling about halfway to the center.

3. Gills

   Attached or running slightly down the stem; close; often forking near the stem; creamy to pale yellow; sometimes becoming spotted brownish in places.

4. Stem

   4-6 cm long; 1-2 cm thick; whitish; dry; smooth; discoloring brownish in places, especially near the base.

5. Flesh

   White; brittle; not changing when sliced.

6. Odor and Taste

   Odor not distinctive; taste mild.

7. Chemical Reactions

   KOH on cap surface orange. Iron salts on flesh and stem surface slowly pink.

8. Spore Print

   Creamy to pale yellow.

9. Microscopic Features

   Spores 6-8.5 x 5-7 µ; with isolated warts up to .8 µ high; connectors scattered, usually not forming reticula. Pileipellis a cutis beneath a turf-like upper layer of elements that are often septate, with subterminal cells inflated and barrel-shaped and the terminal cell clavate, cylindric, or elongated and tapered; pileocystidia clavate to fusiform, up to about 75 x 10 µ, positive in sulphovanillin and refractive-ochraceous in KOH.

Look-Alikes

1. Russula heterophylla

   Has former flesh. Mild tasting

2. Russula virescens

   The Greencracked Brittlegill, is somewhat larger and distinguished by its cap surface crazing as it matures.

3. Amanita phalloides

   Deadly poisonous mushroom with a ring and is not a Russula.

History

This neat brittlegill mushroom was described and given its currently accepted scientific name by Elias Magnus Fries in 1863.

Synonyms of Russula aeruginea include Agaricus graminicolor Secr., Russula furcata var. graminicolor Gillet, and Russula graminicolor (Gillet) Quél.

Russula, the generic name, means red or reddish, and indeed many of the brittlegills have red caps. The specific epithet aeruginea means comes from the Latin prefix aerug-, which can mean blue-gree, green, or deep green.