an order of ascomycetous fungi with closed fruiting bodies (cleistothecia), whose asci are distributed among elements of the basal tissue. In the simplest representatives of Plectascales the fruiting bodies are rudimentary. There are about 130 genera, embracing 270 species. Most species of the families Gymnoascaceae, Onygenaceae, and Aspergillaceae are saprophytes that live in soil, on plant remains, on animal tissues containing horny substances (horns, hooves, feathers), and on other substrates. Some cause diseases of birds and plants.
In the conidial stage, species of the family Aspergillaceae (Aspergillus, Penicillium) spoil various products and form mold. Species of the families Elaphomycetaceae and Terfeziaceae form large fruiting bodies in the soil, some of which are edible (for example, Terfezia). The species Terfezia transcaucasia is found in the USSR. Fungi of the family Myriangiaceae are predominantly parasites of plants. A number of families of Plectascales, such as Myriangiaceae, are sometimes assigned to other orders.