Colonies slow-growing, hyaline to slightly pigmented. Conidiophores erect, verticillately branched, sometimes aggregated into synnemata. Conidiogenous cells in compact whorls, the basal part often swollen, the apex slightly attenauted. Conidia developing in succession from single apical loci, forming dry chains with the oldest at the apex, ellipsoidal to cylindrical, smooth, hyaline or slightly coloured. No teleomorphs are known, but similarities with other anamorphs of the Clavicipitales suggest that the genus belongs to that order. Only one species is well-known.

Nomuraea rileyi (Farlow) Samson

Colonies slow-growing, dense, dusty green. Conidiophores with compact clusters of branches. Conidiogenous cells 4-6 x 2.5-3.5µm, usually short, cylindrical, occasionally with a swollen base, the neck absent or very short. Conidia in dry divergent chains, 3-4 x 2-2.5µm, ellipsoidal, rarely cylindrical, hyaline but green in mass. Nomuraea rileyi is an insect pathogen, attacking larvae and pupae of Lepidoptera and Coleoptera. There has been interest in the use of this fungus as an agent of biological control, though its slow, growth in culture is disadvantageous. See Samson (1974) and Onions (1979) for further information.