Stephanonectria, a new genus of the Hypocreales (Bionectriaceae), and its sporodochial anamorph

A new unispecific genus of the Bionectriaceae, Stephanonectria, is described for Nectria keithii. Stephanonectria is characterised by brown, smooth perithecia that do not change colour in KOH and by a peculiar crown-like structure around the ostiole. The ascospores are covered with short striae that are more or less parallel with the long axis of the spore. The ascospores of different collections vary considerably in length but the differences are not indicative of infraspecific differences or particular geographical patterns. The anamorph shows features typical of several genera, and is here identified as Myrothecium-like. Perithecia of Stephanonectria keithii have been found on dead parts of Brassica sp. and various dead woody substrata in Europe, New Zealand, and possibly also in tropical regions. The anamorph has been isolated from European soil as well.