These structures represent the sexually reproductive spores of several genera of Mucorales. They are usually dark, roughened, 1-celled, and connected to the filaments by short cells called suspensors. They rarely occur apart from asexual fruiting structures and are not normally used exclusively for identification purposes.
Classification: Mucorales (Zygomycota). Ref: Schipper, Samson, and Stalpers 1975; Zycha and Siepmann 1970.