Helvella lacunosa

Scottish naturalist John Lightfoot wrote of it in his 1777 work Flora Scotica, calling Helvella mitra, or curled helvella.[2]

The fungus was formally described by Swedish botanist Adam Afzelius in 1783.[3] Its specific epithet is the Latin adjective lacunosa, meaning "with holes". The generic name was originally a type of Italian herb but became associated with morels.[4] H. sulcata; once separated, because of certain differences in the lobe structure is now dropped, or just a synonym. It was not possible to draw a clear distinction between the two.[5]

Helvella lacunosa not uncommonly appears to be made out of wax.[6] It has an irregularly folded or wrinkled cap which may be shades of slatey grey to black in colour, and measure anywhere from 1 to 10 cm (1⁄2 to 4 in), though usually between 2 and 5 cm (1 and 2 in). The margin can be fused with the wrinkled, ringless stem,[6] which is chambered within, measuring 3–15 cm (1–6 in) high and 1–3 cm wide.[7] The stem may be white when young and darker with age, though may be any shade of grey. The spore print is white, the oval spores average (12) 15–21 x (9) 11–14 μm.[8] Occasionally white capped forms are found. They may be distinguished from the creamy-white coloured Helvella crispa by the latter's furry cap undersurface and inrolled margins when young.[9] Another similar species is H. maculata, which has a brownish cap.[6]

The species can be attacked by Hypomyces cervinigenus or Clitocybe sclerotoidea.[6]

This species is common in Eastern North America and is also found in Europe,[8] Varsey Rhododendron Sanctuary in Sikkim,[10] Japan,[11] and China.[12] It is frequent in the alpine, and temperate zones of both the northern and southern hemispheres.[1] The species occurs under pine, oak and Douglas fir and nearby parkland and lawns.[8] Fruiting bodies appear in late summer and autumn, though have been recorded in winter in California.[8] It often occurs on burnt ground.[13]

Two similar looking species occur in Western North America – Helvella vespertina is associated with conifers and Helvella dryophila is associated with oak. The European Helvella lacunosa has been found in Eastern North America, but rarely in the west.[14]

This species is eaten and regarded highly by some after cooking, though the stems are not eaten.[8] Lightfoot regarded it as edible in 1777,[2] and several guidebooks list it as edible,[13][15] yet this genus is now regarded with suspicion due to the presence of toxic compounds in several related species. It has been reported to cause gastrointestinal symptoms when eaten raw.[9] It may contain small amounts of the toxin monomethylhydrazine, so cooking is required.[7] Roger Phillips calls it "edible but not worthwhile".[16]