Tricholoma fracticum

[ Basidiomycetes > Agaricales > Tricholomataceae > Tricholoma . . . ]

by Michael Kuo

The North American distribution of Tricholoma fracticum is uncertain; to my knowledge it has only been documented in northern California, under conifers. It has a distinctive, two-colored stem that is white near the apex and orangish brown below a well defined . . . well, is it a ring zone or a true ring? It's a little too substantial to qualify as the former, and a little too flimsy for the latter. Other distinguishing features include the reddish brown, sticky (when young) cap and the strongly bitter taste.

Confusion with Tricholoma aurantium can be eliminated quickly, since that species has a finely scaly stem (the orangish brown scales simply terminate near the apex, creating a two-toned appearance without a separating ring or ring zone) and mealy, rather than bitter, taste.

Tricholoma batschii and Tricholoma subannulatum are synonyms.

Description:

Ecology: Mycorrhizal with pines (species of Pinus) and possibly with other conifers; growing scattered or gregariously, sometimes in clusters; recorded from northern California; winter.

Cap: 3-10 cm; broadly convex or nearly flat; slimy or sticky when fresh, but soon dry; reddish brown to orangish brown; smooth or with a few appressed fibers over the center; the margin initially rolled under somewhat.

Gills: Attached to the stem, often by means of a notch; close; whitish to very pale orange, developing brownish discolorations.

Stem: 2-8 cm long; 1-2.5 cm thick; more or less equal, or tapering to the base; whitish near the apex, sometimes discoloring a little brownish; orangish brown below; with a small but clearly defined bracelet of flimsy and gelatinous tissue between the two zones (the result of a cortina-like partial veil that covers the young gills); solid and fleshy.

Flesh: White; not changing on exposure.

Odor and Taste: Taste strongly bitter; odor not distinctive or slightly mealy.

Spore Print: White.

Microscopic Features: Spores 5-7.5 x 3-5.5 µ; smooth; elliptical; inamyloid. Basidia 2-spored (but the European T. fracticum is 4-spored), not basally clamped. Cystidia absent. Clamp connections absent.

REFERENCES: (Brtizelmayr, 1893) Kriesel, 1984. (Breitenbach & Kränzlin, 1991; Shanks, 1996.)

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Cite this page as:

Kuo, M. (2006, October). Tricholoma fracticum. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/tricholoma_fracticum.html