Gymnopus subnudus

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by Michael Kuo

Gymnopus subnudus, also known as Collybia subnuda, is definitely an LBM ("Little Brown Mushroom")--and not a very thrilling one, at that. Microscopic examination is probably required to identify it with certainty (see the details below), but its habitat on sticks and logs, wrinkled brownish cap with a widely lined mature margin, distant or subdistant gills, and frequently bitter taste help narrow down the possibilities. The cap is small, measuring under 4 cm; several similar Gymnopus species are usually larger when mature.

Edibility is not known for Gymnopus subnudus. Do not experiment.

Description:

Ecology: Saprobic; growing scattered, gregariously or in loose clusters on hardwood sticks and logs (also on leaf and acorn litter); late spring through fall; eastern North America from Maine to Illinois.

Cap: 1-3.5 cm, convex with an incurved margin when young, becoming broadly convex, flat, or shallowly depressed; dry; fairly smooth; cinnamon brown to reddish brown when young and fresh, fading to pinkish tan; usually becoming somewhat wrinkled and developing a broadly lined margin.

Gills: Attached to the stem or nearly free from it; distant or nearly so; whitish when young, darkening to pinkish buff.

Stem: 2-7 cm long; up to about 3 mm thick; more or less equal, but usually flaring at the apex; dry; tough; smooth above, finely hairy or finely velvety below; buff, darkening to brownish, reddish brown, or nearly black near the base.

Flesh: Whitish; thin; tough.

Odor and Taste: Odor not distinctive; taste not distinctive or bitter.

Spore Print: Creamy white.

Microscopic Features: Spores: 8.5-11 x 3-4.5 µ; smooth; lacrymoid to elliptical; inamyloid. Pleurocystidia absent. Cheilocystidia up to about 40 µ long; variously shaped; often with fingerlike projections. Pileipellis a tangled cutis of cylindric elements 3-8 µ wide, frequently encrusted (in bands or spirals) with brownish pigment in KOH.

Collybia subnuda is a synonym; Marasmius subnudus is a former name.

REFERENCES: (Ellis ex Peck, 1898) Halling, 1997. (Saccardo, 1902; Kauffman, 1918; Halling, 1983; Halling, 1997; Murphy, 1997; Barron, 1999; Halling, 2004.) Herb. Kuo 08230202, 08190503, 09280504.

Mating studies done by Murphy (1997) determined two groups of Gymnopus subnudus in eastern North America that were incapable of mating, despite sharing similar morphology and nearly identical DNA sequences.

Further Online Information:

Gymnopus subnudus at Roy Halling's Collybia site

Pileipellis elements in KOH

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Cite this page as:

Kuo, M. (2007, April). Gymnopus subnudus. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/gymnopus_subnudus.html