Russula flavisiccans

[ Basidiomycetes > Russulales > Russulaceae > Russula . . . ]

by Michael Kuo

First described from the southern Appalachians by Gerald Bills (1989), Russula flavisiccans is common and widespread in eastern North America's oak-hickory forests. It is a red russula--which is another way of saying it is hard to identify. However, Russula flavisiccans has just enough distinctive features that it is almost possible to identify it without microscopic analysis. The cap is dull and unpolished, and usually a dull pinkish red; the stem is white, without pink flushes; the gills and stem stain and discolor brownish; the taste is somewhat bitter or unpleasant; the spore print is white to creamy; and the flesh and surfaces turn dirty yellow when dried.

Description:

Ecology: Mycorrhizal with oaks and perhaps with other hardwoods in oak-hickory forests; growing alone, scattered, or gregariously; summer and fall; widely distributed in eastern North America.

Cap: 2-11 cm; convex when young, becoming broadly convex to flat, sometimes with a shallow depression; dry; very finely velvety; sometimes developing cracks with maturity; pinkish red to pink when fresh, but often fading to orangish or yellowish pink; sometimes mottled with yellowish or creamy areas; the margin usually not lined at maturity; the skin peeling with difficulty, usually only near the margin.

Gills: Attached to the stem or running slightly down it; close or crowded; white when young but creamy or pale yellowish with maturity; often discoloring and staining brownish.

Stem: 2-6 cm long; 1-3.5 cm thick; white (rarely with a flush of pink); staining and discoloring brownish; dry; fairly smooth.

Flesh: White; unchanging when sliced.

Odor and Taste: Odor not distinctive; taste bitter or creosote-ish and disagreeable.

Spore Print: Creamy.

Dried Specimens: Gills, stem, and flesh turning dull, dirty yellowish; cap surface retaining dull pink colors but showing yellowed flesh in the cracks. The Latin species name of Russula flavisiccans means "drying yellow."

Chemical Reactions: KOH on cap surface pink to red; iron salts on stem surface negative to pinkish or pink.

Microscopic Features: Spores 7-9 x 6.5-8.5 µ; with low warts up to .5 µ high; connectors usually creating reticulated areas. Pleurocystidia more or less clavate; projecting. Pileipellis a cutis beneath a trichoderm with multi-septate hyphal ends, with barrel-shaped sub-terminal cells beneath a fusiform to aciculate terminal cell; pileocystidia cylindric to clavate, to about 220 x 8 µ, ochraceous-refractive in KOH and gray in sulphovanillin.

REFERENCES: Bills, 1989. (Bills, 1989; Kibby & Fatto, 1990; Roody, 2003; Binion et al., 2008.) Herb. Kuo 06230401, 07140703, 07090802, 07190803.

Russula pulchra is very similar; see the comments on the linked page for a comparison.

Further Online Information:

Russula flavisiccans at Russulales News

© MushroomExpert.Com

Cite this page as:

Kuo, M. (2009, March). Russula flavisiccans. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/russula_flavisiccans.html