Xeromphalina cauticinalis

[ Basidiomycetes > Agaricales > Tricholomataceae > Xeromphalina . . . ]

by Michael Kuo

Xeromphalina cauticinalis grows in troops on the debris of conifers, primarily in western North America, although it is occasional in northeastern conifer forests. It has a small, orangish brown to yellowish brown cap, yellow gills that begin to run down the stem, and a tough little stem with a densely fuzzy, orangish base. A drop of KOH on the cap surface produces a bright red reaction. Under the microscope its defining features include irregular and contorted caulocystidia, hyphae that are red in KOH, and ellipsoid spores that are at least faintly amyloid.

Description:

Ecology: Saprobic on the debris (including needle duff and well decayed wood) of conifers; growing gregariously in troops, or occasionally scattered or even alone, usually on the ground; summer and fall; widely distributed and common in western North America, and occasional in northeastern North America.

Cap: Up to 2.5 cm across; convex to broadly convex or flat, often with a shallow central depression; bald; moist; becoming widely lined or pleated on the margin; orange-brown to yellow-brown, often with a darker center.

Gills: Beginning to run down the stem; fairly distant; with many cross-veins; pale yellow.

Stem: 2-8 cm long; 1-2 mm thick; more or less equal above a slightly swollen base; yellowish above, reddish brown to dark brown below; finely hairy or nearly bald above; base covered with rusty hairs.

Flesh: Insubstantial.

Odor and Taste: Taste mild (bitter in var. acida); odor not distinctive.

Chemical Reactions: KOH bright red on cap surface.

Spore Print: White.

Microscopic Features: Spores 4-7 x 2.5-3.5 µ; elliptical; smooth; faintly to moderately amyloid, especially when just produced or when still attached to sterigmata. Pleuro- and cheilocystidia fusiform to narrowly clavate. Caulocystidia irregular and contorted; thin- or thick-walled. Clamp connections present.

REFERENCES: (Withering) Kühner & Maire, 1934. (Miller, 1968; Smith, Smith & Weber, 1979; Arora, 1986; Evenson, 1997; Barron, 1999; Miller & Miller, 2006.) Herb. Kuo 08051002, 08071002.

Xeromphalina cauticinalis var. acida is nearly identical but features slowly to instantly bitter flesh.

KOH

Spores

Caulocystidia

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Cite this page as:

Kuo, M. (2010, November). Xeromphalina cauticinalis. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/xeromphalina_cauticinalis.html