Major Groups > Gilled Mushrooms > Pale-Spored > Collybioid > Gymnopus alkalivirens


Gymnopus alkalivirens

[ Basidiomycetes > Agaricales > Marasmiaceae > Gymnopus . . . ]

by Michael Kuo

This small, dark brown saprobe appears in northern and montane areas of North America, and can be recognized quickly if a drop of KOH or ammonia is applied to its cap, producing a green color change. But without the chemical test . . . well, you're looking at a little brown mushroom with a white spore print and no distinctive odor or taste. In short, you may need to unpack your microscope.


Ecology: Saprobic; growing alone, scattered, gregariously, or in clusters on soil, leaf and needle litter, woody debris, and among mosses or ferns; found in hardwood, conifer, and mixed forests; summer and fall; apparently widely distributed in northern North America, the Appalachians, and the Rocky Mountains.

Cap: 1-4.5 cm; convex, becoming broadly convex or nearly flat, with a low central bump; greasy; bald; sometimes becoming somewhat wrinkled; dark brown to dark purplish brown, developing a pale margin and eventually fading to cinnamon or buff overall; the margin sometimes becoming lined.

Gills: Attached to the stem or nearly free from it; close; medium brown to pale brownish.

Stem: 3-8 cm long; up to about 5 mm thick; more or less equal, or with a slightly swollen base; dry; bald; colored like the cap; with brownish fuzz near the base.

Flesh: Whitish to brownish; thin.

Odor and Taste: Not distinctive.

Chemical Reactions: Ammonia or KOH promptly green on all surfaces.

Spore Print: White.

Microscopic Features: Spores: 5-8 x 2.5-4 µ; smooth; lacrymoid to elliptical; inamyloid. Pleurocystidia absent. Cheilocystidia scattered; cylindric to subclavate; sometimes somewhat lobed or with projections; to about 70 µ long. Pileipellis a cutis of branched elements 3-5 µ wide; greenish in KOH; sometimes encrusted with brown pigment. Hyphae of the gill, cap, and stem trama encrusted with scattered brown granules.

Collybia alkalivirens is a synonym.

REFERENCES: (Singer, 1948) Halling, 1997. (Smith, Smith & Weber, 1979; Halling, 1981; Halling, 1983; Phillips, 1991/2005; Lincoff, 1992; Halling, 2004.) Herb. Kuo 08041001.

Further Online Information:

Gymnopus alkalivirens at Roy Halling's Collybia site
Collybia alkalivirens at Roger's Mushrooms


Gymnopus alkalivirens

Gymnopus alkalivirens

Gymnopus alkalivirens

Gymnopus alkalivirens

Gymnopus alkalivirens

Gymnopus alkalivirens

Gymnopus alkalivirens
Brown pigment granules

© MushroomExpert.Com

Cite this page as:

Kuo, M. (2013, February). Gymnopus alkalivirens. Retrieved from the MushroomExpert.Com Web site: