Apomelasmia urticae
Anamorph: Conidial stromata 1-4 mm long, effuse, black, smooth and glossy, the conidiomata visible from the surface as shallow domed structures. Conidiomata to 200 µm diam, immersed, effuse, separate or confluent, of thin-walled pale brown angular cells, overlain by a layer of dark brown thick-walled cells which extend beyond the locules and cover the substrate, opening by irregular fissure. Conidiophores cylindrical, sparsely branched at the base, 1- to 2-septate, with acrogenous conidia formed all around the locular cavity. Conidiogenous cells 9-16 x 3.5-4 µm, cylindrical or long flask-shaped, hyaline or pale brown, smooth, proliferating percurrently, determinate, integrated or discrete, collarette and channel minute. Conidia 17-25 x 3.5-4.5 µm, ± cylindrical to fusiform, straight or ± curved, hyaline, simple, smooth, thin-walled, guttulate.
Teleomorph: a teleomorph variously assigned to Aporhytisma or Diaporthopsis has been claimed, but the connection between the morphs needs confirmation.
Not evaluated, but the species is reasonably common and unlikely to be threatened.
On dead stems of Urtica dioica.
Scattered throughout Britain from Devon and Surrey in the south to West Sutherland in the north. Almost certainly overlooked.