Diaporthe beckhausii  

Description contributed by Graham Kinsey, CABI.

Anamorph: Phomopsis beckhausii (Cooke) Traverso (1906). Conidiomata 500 x 250 µm. Conidiophores 15 x 1.5 µm. Alpha-conidia 8-12 x 2-3 µm; beta-conidia 8-13 x 1-1.5 µm.

Teleomorph: Stromata on host surface as small pustulate ruptures with one or a few ostioles, pustules small and not prominent, dorsal zone often absent when the perithecia are mature. Ascomata 250-500 µm diam, scattered singly, irregularly crowded or loosely grouped, usually collectively erumpent, ostioles short-cylindrical and barely erumpent. Asci 40-48 x 5-7 µm, clavate. Ascospores 10-13(-15) x 2.5-3.5(-4) µm, fusiform-ellipsoid, straight, constricted at the septum.

The above description is of Wehmeyer's host-restricted typical form on Viburnum.