Description contributed by Graham Kinsey, CABI, based on Wehmeyer (1933).
Anamorph: Phomopsis diaporthes-macrostomae Traverso (1906). Conidiogenous cells 32-36 x 1 µm. Alpha-conidia 8-9 x 3 µm.
Teleomorph: stromata on host surface as pustulate clusters of ostioles, surface of bark irregularly blackened, ventral zone present or absent. Ascomata usually in large crowded clusters or sometimes scattered, ostioles fine-filiform and sinuous. Ascospores 11-14 x 2.5-3.5 µm.
Wehmeyer considered this to belong within the D. rudis aggregate.