Stilbocrea walteri sp. nov., an unusual species of Bionectriaceae.

The new species Stilbocrea walteri is described and illustrated from Quercus ilex collected in Portugal. Phylogenetic analyses of LSU rDNA, rpb1, rpb2 and tef1 sequence matrices place S. walteri in the Bionectriaceae, Hypocreales, within a clade of specimens morphologically identified as Stilbocrea macrostoma, the generic type of Stilbocrea. Stilbocrea walteri differs from S. macrostoma in dark olive green to blackish ascomata basally immersed in a stroma, KOH+ and LA+ ascomata and the lack of a stilbella-like asexual morph on natural substrate and pure culture. A simple phialidic asexual morph is formed in pure culture. To enable a morphological comparison, Stilbocrea macrostoma is illustrated.