Colonies: very variable in size, ranging from small patches 1-2 mm diam. but often extensive and sometimes completely encircling stems, olivaceous when young and black when mature, conspicuously felty.
Anamorph: Conidiophores poorly differentiated from vegetative hyphae but with slightly wider, darker and thicker cells. Conidiogenous cells not clearly distinguishable in morphological terms from their subtending cells, 7-9 µm diam., proliferating sympodially and irregularly. Conidia sometimes formed from several loci simultaneously and in branched chains, 20-45 (-70) x 5-9 µm, 3- to 10- (mostly 4- to 5-) septate, ± cylindrical to cylindric-fusiform, straight or slightly curved, the ends rounded, pale olivaceous to mid brown, becoming finely echinulate.