The genus Geoglossum has the spore body simple, erect, and club-shaped, and entirely black. The spore surface is terminal.

Geoglossum hirsutum

Geoglossum hirsutum is black, dry, and everywhere velvety. Lanceolate, ovate, oblong, or almost round, often irregular. The spore-bearing portion is one-quarter to one-half the length of the fungus.

Geoglossum glabrum

Geoglossum glabrum is dry, black, or brownish black, sometimes tinged with olive or purple. Club-shaped or sometimes laterally compressed. The spore-bearing portion not sharply distinct from the stem below.