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Lyophyllum fumosum

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

by Michael Kuo

Lyophyllum fumosum is a member of the Lyophyllum decastes species group, featuring an innately fibrous cap surface and a mealy odor. The "true" Lyophyllum decastes, in contrast, features a bald cap and and an indistinct odor. Other features, both macro- and microscopic, are virtually identical--leading some mycologists (e.g. Breitenbach & Kränzlin, 1991) to question whether the separation of species is legitimate.


Ecology: Saprobic; usually growing in dense clusters in disturbed soil (roadbeds, paths, landscaping areas, and so on), or occasionally growing alone or scattered (and sometimes occurring in woods); summer and fall; North American distribution uncertain but probably widely distributed. The illustrated collection is from southwestern Colorado.

Cap: 2-13 cm; convex, becoming broadly convex, flat, or broadly bell-shaped; moist when fresh; with innate radiating fibers, at least over the center; dark grayish brown to brown or yellowish brown.

Gills: Attachment variable (broadly attached to the stem, sometimes by a notch, or beginning to run down it); close; whitish to cream colored or faintly grayish.

Stem: 3-10 cm long; up to 2 cm thick; smooth; more or less equal, or tapered to base when tightly clustered; dry; whitish, sometimes becoming brownish.

Flesh: White; firm; not changing on exposure.

Odor and Taste: Taste mild or slightly bitterish; odor mealy.

Chemical Reactions: KOH on cap surface negative.

Spore Print: White.

Microscopic Features: Spores 5-7 µ; round or nearly so; smooth; inamyloid. Cystidia absent. Basidia with siderophilous granules when mounted in acetocarmine. Clamp connections present.

REFERENCES: (Persoon, 1801) Orton, 1960. (Fries, 1821; Saccardo, 1887; Moser, 1983; Breitenbach & Kräzlin, 1991; McNeil, 2006.) Herb. Kuo 08150710.

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Lyophyllum fumosum

Lyophyllum fumosum

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

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