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Helvella sulcata   sensu N. S. Weber

by Michael Kuo, 11 April 2025

How cool is this little mushroom?! Like a little gray saddle sitting on a fluted pedestal, Helvella sulcata is usually found fruiting around well decayed hardwood stumps. Its color ranges from nearly black to nearly white, but its overall shape and proportions remain stable.

The Midwestern mushroom described and illustrated here is probably not, actually, Helvella sulcata, which by current definitions is a European species with a black cap (Skrede et al. 2017). But sulcata-like phylogenetic species are popping up all over the globe (or, perhaps better said, all over every Helvella graduate student's DNA study), and North American versions have yet to be addressed with any sustained focus. Thus, there may be several sulcata-ish species in North America, or even among the 6 collections described and illustrated here, which range in color from nearly black to nearly white (intermediate specimens are often found, however, within close range, suggesting the possibility that the black, gray, and whitish specimens may represent the same species).

In 1972 Nancy Weber described what she called "Helvella sulcata" on the basis of dozens of Michigan collections made primarily by Alex Smith (her father) and held in the University of Michigan's herbarium. She characterized the species as "saddle shaped with a shallow to acute sinus," with a "gray to black" cap, appearing "frequently on rotting hardwood debris" in upland woods. However, she also documented a "late season pale form," appearing in summer and fall, with a "pale gray to drab" cap, and included an illustration of a nearly white "extreme example" of the pale form.

Thanks to Django Grootmyers and Michelle Lierl for documenting, collecting, and preserving Helvella sulcata for study; their collections are deposited in The Herbarium of Michael Kuo.

Description:

Ecology: Possibly mycorrhizal; growing scattered or gregariously on and around well decayed hardwood stumps in upland woods; spring through fall; originally described from Sweden (Afzeliius 1783) and epitypified from Norway (Skrede et al. 2017); European distribution uncertain due to confusion with Helvella lacunosa; in North America first described as separate from Helvella lacunosa by Weber (1972), citing collections from Michigan and British Columbia. The illustrated and described collections are from Illinois. Indiana, Maine, and Ohio.

Cap: 15–30 mm high and 15–25 mm mm wide; saddle-shaped, three-lobed, or loosely and irregularly lobed or folded (especially when young); sometimes nearly black when young, but soon pale to dark gray—or whitish to very pale yellowish brown; bald; margin ingrown with the stem in places when mature.

Sterile Surface: Bald or very finely pubescent in places; pale gray to whitish; exposed when young or in irregular caps, but frequently not exposed.

Stem: 10–30 x 4–13 mm; often tapered to base; extensively ribbed longitudinally, with pockets sometimes developing between the ribs in older specimens; ribs not extending onto the sterile surface of the cap; white to whitish, grayish, or brownish; basal mycelium white.

Flesh: Thin and brittle; gray in cap and whitish in stem.

Odor: Not distinctive.

Chemical Reactions: KOH on surfaces negative. Iron salts on surfaces negative.

Spore Print: White.

Microscopic Features: Spores 14–18 x 10–12 µm; ellipsoid; smooth; with one large oil droplet; hyaline in water and in KOH. Asci 8-spored. Paraphyses 4–7 µm wide; cylindric with subclavate to clavate apices; smooth; hyaline in KOH. Excipular surface a hymeniform layer of terminal cells 30–60 x 6–16 µm, clavate to obpyriform, smooth or a little roughened, hyaline in KOH. Below hymeniform layer a transition to cylindric-swollen textura intricata.

REFERENCES: A. Afzelius, 1783. (Anderson & Ickis, 1921; Seaver, 1928; Weber, 1972; Abbott & Currah, 1988; Bessette, Miller, Bessette & Miller, 1995; Abbott & Currah, 1997; Nonis, 2001; McNeil, 2006; Landeros & Gúzman-Dávalos, 2013; Kuo & Methven, 2014; Landeros et al., 2015; Skrede et al., 2017; Skrede et al., 2020; Landeros et al., 2021.) Herb. Kuo 08070902, 05281102, 07241501, 07251701, 06171801, 07052401.

This site contains no information about the edibility or toxicity of mushrooms.

Spores

Parapyses

Excipular surface

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Cite this page as:

Kuo, M. (2025, April). Helvella sulcata. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/helvella_sulcata.html