Collybia tuberosa

[ Basidiomycetes > Agaricales > Tricholomataceae > Collybia . . . ]

by Michael Kuo

This cool little mushroom is widely distributed, and is frequently found in late summer and fall. Like its close cousins, Collybia cookei and Collybia cirrhata, Collybia tuberosa grows from the decaying remains of other mushrooms--often species of Lactarius or Russula. Sometimes, however, the host mushroom is so far decayed that it is recognizable as a former mushroom only to true myco-geeks who have spent many hours of their lives prying into smelly, blackened fungal remains.

Unfortunately for normal people, a thorough investigation of the mushroom's substrate is necessary to distinguish it from its relatives. Collybia tuberosa grows from little knots of tissue, called "sclerotia" in Mycologese. You will need to pry around with your fingers or a stick to find the sclerotia. If they are absent, you may have found Collybia cirrhata. If sclerotia are present, you have found Collybia tuberosa if they are more or less elliptical and reddish brown (see illustration). Collybia cookei has rounder, yellowish sclerotia.

Collybia tuberosa is much too small and inconsequential to consider as an edible.

Description:

Ecology: Presumably saprobic; growing on the remains of decayed mushrooms (especially Lactarius and Russula species), or occasionally on humus; under hardwoods or conifers; summer and fall (winter in coastal California); widely distributed in North America.

Cap: 2-10 mm, convex with a somewhat inrolled margin when young, becoming broadly convex to flat, with a central depression; dry or moist; more or less smooth; sometimes lined on the margin; whitish.

Gills: Attached to the stem; close or almost distant; whitish or pale pinkish.

Stem: 1-5 cm long; about 1 mm thick; more or less equal; dry; often minutely dusted at the apex and/or base; whitish to pinkish; becoming hollow; attached to sclerotia which are tear-shaped or elliptical, reddish brown, and measure 3-12 x 2-5 mm.

Flesh: Whitish; thin.

Spore Print: White.

Microscopic Features: Spores 4-6 x 3-3.5 µ; smooth; more or less elliptical; inamyloid.

REFERENCES: (Bulliard: Fries) Kummer, 1871 (Smith, Smith & Weber, 1979; Halling, 1983; Arora, 1986; Phillips, 1991/2005; Lincoff, 1992; Barron, 1999; Halling, 2003.) Herb. Kuo 09130402.

Further Online Information:

Collybia tuberosa at Tom Volk's Fungi
Collybia tuberosa at Roy Halling's Collybia site

Sclerotia

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Cite this page as:

Kuo, M. (2004, September). Collybia tuberosa. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/collybia_tuberosa.html