Helvella elastica

Helvella elastica, commonly known as the flexible Helvella or the elastic saddle, is a species of fungus in the family Helvellaceae of the order Pezizales. It is found in Asia, Europe, and North America. It has a roughly saddle-shaped yellow-brown cap atop a whitish stipe, and grows on soil in woods. Another colloquial name is the brown elfin saddle.

Description
The fruit body of the fungus is grayish or olive-brown, saddle- or mitral-shaped (i.e., resembling a double mitre) and is attached only to the top of the stipe; it may be up to 3.5 cm wide. The underside is white. The stipe is white, solid or filled with loosely stuffed hyphae, has a smooth surface, and is up to 8 cm long by 1 cm thick. The flesh of H. elastica is brittle and thin. The odor and taste are indistinct.

Microscopic characteristics
The spores are oblong to elliptical in shape, translucent (hyaline), contain one central oil drop (guttulate), and have dimensions of 18–22 by 10–14 μm; young spores have coarse surface warts, while older ones are smooth. The spore-bearing cells, the asci, are 260 by 17–19 μm. The paraphyses (sterile cells interspersed between the asci) are club-shaped, filled with oil drops, sometimes branched, and are 6–10 μm at the apex.

Similar species
The closely related fungus Helvella albipes has a thicker stipe and a two- to four-lobed cap. H. compressa and H. latispora have cap edges that are curled upward, rather than inward as in H. elastica. H. maculata has a similar cap but a ribbed stem. Gyromitra infula has an orange and more defined cap.

Distribution and habitat
This fungus is typically found fruiting singly, scattered, or clustered together on the ground or on wood in coniferous and deciduous woods. It has been found in Europe, western North America, Japan, and China. It is present in summer and fall.

Potential toxicity
Consumption of this fungus is not recommended as similar species in the family Helvellaceae contain the toxin gyromitrin.

Fibrinolytic activity
A 2005 Korean study investigated the ability of extracts from 67 different mushroom species to perform fibrinolysis, the process of breaking down blood clots caused by the protein fibrin. H. elastica was one of seven species that had this ability; the activity of the extract was 60% of that of plasmin, the positive control used in the experiment.