Helvella macropus species cluster

[ Ascomycetes > Pezizales > Helvellaceae > Helvella . . . ]

by Michael Kuo

A number of Helvella species form a cluster of hard-to-distinguish mushrooms that have cup-shaped or disc-shaped to flat caps and finely hairy, skinny stems that are not ribbed. The true Helvella macropus is easily distinguished with the use of a microscope, however; its spores are spindle-shaped rather than elliptical. Helvella macropus is described below; some information on look-alike species follows.

Helvella macropus is frequently the victim of parasitism on the part of Hypomyces cervinigenus. The top specimen in the third illustration is an example.

Edibility for the mushrooms in this cluster is not known; they should not be eaten.

Description:

Ecology: Uncertain (potentially saprobic and/or mycorrhizal, like the morels); growing alone or gregariously on the ground under hardwoods or conifers, or on rotting wood; summer to fall (winter in California); widely distributed in North America.

Cap: 1-5 cm; cup-shaped or disc-shaped, occasionally nearly flat; upper surface brownish, smooth; undersurface colored like the upper surface, finely hairy (especially near the margin; use a magnifying glass).

Flesh: Thin.

Stem: 1-5 cm long; to .5 cm thick; more or less even; sometimes with clefts near the base in age; colored like the undersurface of the cap; finely hairy.

Microscopic Features: Spores 21-24 x 10.5-12.5 µ; spindle-shaped; smooth or slightly rough; with one large central oil droplet and another, smaller oil droplet at each end.

REFERENCES: (Fries, 1822) Karsten, 1870. (Smith Weber, 1972; Arora, 1986; Lincoff, 1992; Abbott & Currah, 1997.) Herb. Kuo 07209401, FMP 06170206, 05230302, 06010407.

Helvella macropus var. brevis is nearly identical, but is shorter (stem under 2 cm long), and has shorter spores (18-23 x 10.5-12 µ).

Several species are similar in macrofeatures, but have elliptical rather than spindle-shaped spores. They include Helvella villosa, with a darker cap that seems to fold over more and become flat or even convex; Helvella corium, a small northern species with a jet black cap; Helvella cupuliformis, with a pale underside and stem (illustrated, bottom); and Helvella pallidula, with pale, drab colors.

Further Online Information:

Helvella macropus at Fungi of Poland

Helvella cupuliformis

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Cite this page as:

Kuo, M. (2003, February). Helvella macropus species cluster. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/helvella_macropus.html