Diaporthe fibrosa  

Description contributed by Graham Kinsey, CABI, based on Wehmeyer (1933).

Anamorph: Phomopsis fibrosa (Sacc.) Höhn. (1916). Alpha-conidia 6-13 x 2-5 µm.

Teleomorph: stromata variable in size, appearing on small twigs as small conical to fusoid pustules 0.2-1 mm diam and with a central cluster of ostioles, on larger twigs forming larger fusiform to elliptical discs 1-2.5 x 0.5-1.5 mm which rupture and throw back the covering bark. Ascomata 480-720 x 320 x 720 µm, spherical to somewhat flattened, clustered in the pustulate areas beneath a well-developed ectostroma through which the stout-cylindrical ostioles are erumpent. Asci 80-95 x 8-10 µm, clavate, with a refractive apical ring. Ascospores 11-14(-16) x 6-8 µm, broadly fusiform-ellipsoidal, with obtuse ends, constricted at the septum, with a single large guttule in each cell.