Colonies developing in the hymenium of the host, scarcely visible macroscopically. Mycelium brownish, septate, smooth-walled, not constricted at the septa, ca 1 µm diam.
Conidiophores hardly distinguished from vegetative hyphae, frequently branched, pale brown, smooth-walled, septate, distinctly constricted at the septa, 25-50 µm long and 1.7-3 µm thick. Conidiogenous cells monoblastic, rarely polyblastic, not differentiated from the conidiophore cells, subcylindrical to ellipsoidal, pale brown. Conidia subglobose to ellipsoidal, brownish, aseptate or rarely 1-septate, thin- and smooth-walled, catenate, with chains often branched, composed of 1-20 conidia, 3-4.5 x 2.5-4 µm in size. Teleomorph: not known.