Helvella acetabulum (species cluster)

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

by Michael Kuo

The mushrooms in this "cluster" have cup-like caps positioned on deeply ribbed, well developed, often thick stems. The crucial identifying feature is the way the ribs extend from the stem onto the underside of the cap. The "true" Helvella acetabulum is described below; see the comments afterwards for the gory details on separating the species in the cluster, and on look-alikes.

Edibility for these mushrooms is not known; they should not be eaten.

Description:

Ecology: Uncertain (potentially saprobic and/or mycorrhizal, like the morels); growing alone or gregariously, terrestrially under hardwoods; spring and early summer (winter and spring in California); widely distributed.

Cap: 2-8 cm; cup-like; sometimes flat in age; upper surface brown; undersurface also brown to yellow-brown, sometimes paler near the stem, finely hairy near the margin (use a magnifying glass), with forked ribs extending from the stem, sometimes almost to the margin; the margin more or less even.

Flesh: Thin; brittle.

Stem: To 9 cm long; to 3 cm thick; becoming broader near the cap; deeply ribbed; the ribs extending onto the undersurface of the cap; cream colored.

Microscopic Features: Spores 16-18 x 11-13.5 µ; elliptical; smooth; with one central oil droplet.

REFERENCES: (Fries, 1822) Quélet, 1886. (Smith Weber, 1972; Arora, 1986.) Herb. FMP 06030401.

Paxina acetabulum is a former name for this species.

Helvella costifera has a gray to grayish brown cap that lacks yellow tones; its stem features blunt-edged, rather than sharp-edged, ribs. "Helvella griseoalba," described by Nancy Weber (1972), has been synonymized with Helvella costifera.

Helvella leucomelaena and Helvella queletii are superficially similar, but the former has a less developed stem that is often buried underground, and the later has a strongly inrolled cap margin. The ribs do not extend onto the cap's undersurface in either species.

Further Online Information:

Helvella acetabulum at MykoWeb
Helvella acetabulum at Fungi of Poland

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Cite this page as:

Kuo, M. (2005, January). Helvella acetabulum species cluster. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/helvella_acetabulum.html