Mycenastrum corium

Sporocarp
Fruiting body sub-hypogeous to emergent, 7–17 cm broad, 5–8 cm tall, compressed globose to turbinate, abruptly tapered to a pointed base, attached by a well developed tuft of mycelium to the substrate; exoperidium, white to buff, relatively thick, in age forming a thin, patchy covering; endoperidium thick (up to 2 mm) tough, leathery, blackish-brown; spores released by splitting of the endoperidium into irregularly shaped sections; gleba whitish, maturing olive-brown to dark-brown, drying medium-brown; coarse mycelial strands seen near the base of the gleba; subgleba absent; odor somewhat pungent, earthy; taste slightly astringent.

Spores
Spores 8–11.5 µm,globose, thick-walled, warted, partially to completely reticulate, with a central droplet; pedicel inconspicuous,< 1 micron long; capillitium of individual elements, thick-walled, not pitted, occasionally branched, with distinctive thorn-like projections; spores medium-brown.

Habitat
Solitary, scattered, or in rings, occasionally clustered; fruiting in pastures or around compost heaps after fall rains; occasional.

Edibility
Unknown.

Comments
The hallmark of this thick-skinned puffball is a peridium that splits into sections sometimes giving dried sporocarps a star-like shape. In this respect, Mycenastrum corium is very similar to Calvatia pachyderma. Though not closely related, the latter also has a thick-walled, splitting peridium that sometimes recurves in age, but lacks the thick mycelial strands seen at the base of the gleba of Mycenastrum corium. Additionally, it differs microscopically with a different type of capillitium and nearly smooth, often ovoid spores. Other puffballs with peridia that split into sections include Bovista pila and Scleroderma polyrhizum. Bovista pila is distinguished by a relatively thin, parchment-like peridium, that often has a metallic sheen, and elastic gleba, while Scleroderma polyrhizum, though possessing a thick-walled peridium, has a purplish-brown gleba, and also lacks strands of thickened mycelium at the base of the gleba.