Russula uncialis

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

by Michael Kuo

Red species of Russula are confoundingly difficult to separate from one another, but Russula uncialis has enough distinguishing features to make it identifiable--perhaps even without microscopic analysis. To wit, these features are:

• Small to medium size, and fragile stature.
• Pure white spore print and gills.
• Mild taste and nondescript odor.
• A pink to red cap that is not mottled but sometimes has a darker center.
• A stem that is often flushed with the cap color.
• Habitat under hardwoods in eastern North America.

If you have matched all of these features, the odds are high that your mushroom is Russula uncialis. Microscopic details (see below) will confirm your identification.

Edibility is not recorded for Russula uncialis. Do not experiment.

Description:

Ecology: Mycorrhizal with hardwoods, especially oaks; growing alone or gregariously; summer and fall; eastern North America.

Cap: 2-6 cm; convex, becoming broadly convex to flat with a shallow depression; rather thin and fragile; sticky when wet and fresh, but soon dry; smooth or finely dusted; pink to blood red or rose red; evenly colored, but often with a slightly darker center; the margin becoming lined at maturity; the skin peeling fairly easily.

Gills: Attached to the stem; close; a few forked near the stem; white; unchanging.

Stem: 1-5 cm long; up to 1 cm thick; more or less equal; smooth; white, often flushed with the cap color.

Flesh: White; unchanging on exposure.

Taste: Mild; odor not distinctive.

Spore Print: White.

Chemical Reactions: KOH on cap surface negative; iron salts negative on stem surface.

Microscopic Features: Spores 7-9 x 5.5-7 µ; broadly elliptical; with warts projecting under 1 µ; connecting lines scattered and sparse, not forming reticula. Pileocystidia absent.

REFERENCES: Peck, 1887. (Kauffman, 1918; Graham, 1944; Kibby & Fatto, 1990.) Herb. Kuo 06140304.

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