Beih. Nova Hedwigia 51: 35. 1975.
Common Name: none
Synonym: Paxina compressa Snyder
Pileus saddle-shaped, two to occasionally three-lobed, 2.5-4.0 cm broad, separated by a narrow gap; margin when young partially inrolled over the upper, fertile surface, in age flattened against the stipe; upper, fertile surface smooth, dry, dull medium grey to grey-brown; lower surface sterile, pallid to pale grey, pubescent; flesh thin, brittle, pale-grey, unchanging when injured or cut; odor and taste mild.
Stipe 4-10 cm tall, 0.5-1.0 cm thick, straight, occasionally somewhat sinuous, round, compressed to furrowed, stuffed or hollow at maturity, equal to tapering to a narrowed apex; surface minutely hairy (use hand lens), white to pallid.
Spores 18-21 x 12-13 µm, oblong to elliptical, smooth, non-amyloid, with a large central oil drop.
Scattered to gregarious in mixed hardwood/conifer woods; fairly common under tanbark oak (Lithocarpus densiflora)and redwood (Sequoia sempervirens); fruiting during the spring.
Helvella compressa is characterized by a dark grey to grey-brown, saddle-shaped cap, a pubescent, pale sterile lower surface and a relatively smooth, white stipe. Helvella albella is similar but smaller, has a less pubescent sterile surface, and according to Nancy Smith Weber, fruits during the fall. If it occurs in the Bay Area it is rare as it is not among the herbarium collections at San Francisco State University. Helvella elastica is another look-alike but can be distinguished by less steeply peaked saddle-lobes, a margin which does not curl over the fertile surface when young, and a glabrous, not hairy, sterile, lower surface.
Abbott, S.O. & Currah, R.S. (1997). The Helvellaceae: Systematic revision and occurrence in northern and northwestern North America. Mycotaxon 62: 1-125.
Snyder, L.C. (2001). New and Unusual Discomycetes of Western Washington. Mycologia 28(5): 483-488. (Protologue)
Weber, N.S. (1975). Notes on western species of Helvella. I. Nova Hedwigia Beiheft 51: 25-38.