Three new species of (Acarosporales, Acarosporaceae) from southwestern North America.

The discovery and study of three new species of from Southwestern North America, , , and , adds not only to the diversity of the genus and family but generated new insights into the occurrence of two ascus types in the genus and the variety of conidiogenous cells and conidia. now includes 15 species with a mainly Holarctic distribution (Asia, Europe, North America) and one species in Australia. A key is supplied to the genus.