Vinegar Cup

Appearance

''Helvella acetabulum'' has a deeply cup-shaped fruit body that is up to 8 cm in diameter, and 4 cm deep. The inner spore-bearing surface, the hymenium, is brown, and may be smooth or slightly wavy; the exterior surface is cream-colored, and is covered with minute "hairs". The ribs start from the cream-colored stem and extend almost to the edge of the fruit body. The stem is typically 1 to 6 cm tall by 1 to 3 cm thick. The odor and taste of this mushroom are not distinctive.

The spores are smooth, elliptical, translucent , and contain a single central oil droplet; they have dimensions of 18–20 by 12–14 µm. The spore-bearing cells, the asci, are 350–400 by 15–20 µm, are operculate—meaning they have an apical "lid" that releases the spores. The tips of the asci are inamyloid, so they do not adsorb iodine when stained with Melzer's reagent. The paraphyses are club-shaped, and have a pale brown color, with tips that are up to 10 µm thick.

Distribution

This fungus is widespread in North America and Europe. In North America, the distribution extends north to Alberta, Canada. In Mexico, it has been collected from State of Mexico, Guanajuato, Guerrero, and Tlaxcala. It is also found in Israel, Jordan, Turkey, Iran China and Japan.

Habitat

The fruit bodies grows solitary, scattered, or clustered together on soil in both coniferous and deciduous woods, typically in spring and summer. A preference for growing in association with coast live oak has been noted for Californian populations.

Uses

Although the edibility of the fruit bodies is often listed as "unknown", consumption of this fungus is not recommended as similar species in the family Helvellaceae contain varying levels of MMH. MMH can be removed by boiling in a well ventilated area but consumption of any MMH producing mushroom is not advisable Roger Phillips lists the species as poisonous.