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Lyophyllum geminum

[ Basidiomycetes > Agaricales > Tricholomataceae > Lyophyllum . . . ]

by Michael Kuo

Lyophyllum geminum is one of many small to medium-sized, gray-staining species in the genus Lyophyllum. It is a rather non-descript, drab mushroom requiring microscopic analysis for identification: it has fairly large, flask-shaped spores and a non-gelatinized pileipellis. It was originally described from Mt. Rainier National Park; the illustrated collection was made in Colorado. A variety with a strong, green-corn odor (Lyophyllum geminum var. olens) was originally described from northern Michigan and has since been identified from Québec.


Ecology: Presumably saprobic; growing alone, scattered, or gregariously in montane areas; summer and fall; western North America.

Cap: 2.5-6 cm; convex, becoming broadly convex or flat; moist when fresh; bald; grayish brown to pale gray; fading markedly to brownish buff as it dries out; the margin at first inrolled, not lined.

Gills: Broadly attached; close or nearly distant; whitish, with the edges staining and aging gray.

Stem: 3-4 cm long; up to about 1.5 cm thick; smooth; more or less equal, or slightly club-shaped; dry; whitish, staining slowly grayish where handled.

Flesh: White; changing slowly to grayish or gray on exposure.

Odor and Taste: Not distinctive.

Chemical Reactions: KOH on cap surface negative.

Spore Print: White.

Microscopic Features: Spores 8.5-11.5 x 4-6 µ; flask-shaped to inequilateral and "hump-backed"; smooth; inamyloid. Cystidia absent. Basidia 31-36 x 7-9 µ; with siderophilous granules when mounted in acetocarmine. Pileipellis a cutis; not gelatinized or only very slightly so; elements brownish in KOH, 3-5 µ wide. Clamp connections present.

REFERENCES: H. Clemençon & A. H. Smith, 1983. Herb. Kuo 08200801.

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Lyophyllum geminum

Lyophyllum geminum

Lyophyllum geminum

Lyophyllum geminum

Lyophyllum geminum

Cite this page as:

Kuo, M. (2010, May). Lyophyllum geminum. Retrieved from the MushroomExpert.Com Web site:

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