European species of Hypocrea part II: species with hyaline ascospores

Abstract

To date 75 species of Hypocrea/Trichoderma forming teleomorphs are recognised in Europe. The 56 hyaline-spored species are here described in detail and illustrated in colour plates, including cultures and anamorphs. This number includes 16 new holomorphs, two new teleomorphs and nine anamorphs of species previously described as teleomorphs. Phylogenetic placement and relationships of the species are shown on the strict consensus tree, based on sequences of RNA polymerase II subunit b (rpb2) and translation elongation factor 1 alpha (tef1) exon, comprising 135 species of the genus Hypocrea/Trichoderma. All available holotypes of species described from Europe including some from North America have been examined. A dichotomous key to the species is provided primarily utilising ecological and morphological traits of the teleomorphs and, where necessary, morphology of the anamorphs and cultures, and growth rates. Species descriptions are subdivided among five chapters, arranged primarily according to the larger phylogenetic clades, viz. section Trichoderma with 13 species, the pachybasium core group with 13 species including four species with stipitate stromata (‘Podostroma’), species forming large effused stromata with 10 species including the section Hypocreanum, 9 species of the Brevicompactum, Lutea and Psychrophila clades, and 11 residual species of various smaller clades or of unknown phylogenetic placement. Finally, a list comprising dubious names and species excluded from Hypocrea that are relevant for Europe, or species claimed to occur in Europe by other authors is provided. Hypocrea minutispora is by far the most common species in Europe. For H. moravica, H. subalpina and H. tremelloides the anamorphs are newly described. The anamorphs of the latter two species and H. sambuci produce hyaline conidia on unusual structures new to Trichoderma. These three species form a new subclade of the morphologically strikingly different section Longibrachiatum, which is currently only represented by H. schweinitzii in Europe as a holomorph. The subclade is not named yet formally due to low statistical support. H. fungicola f. raduli is described as the new species H. austriaca, while H. hypomycella was found not to belong to Hypocrea. The typification of H. pilulifera, H. tremelloides and H. lutea has been clarified. Gliocladium deliquescens, the anamorph of H. lutea, is combined in Trichoderma. Species are epitypified where appropriate. Anamorph names are established prospectively to avoid numerous new combinations in future when they may be possibly used as holomorphic names if the ICBN is altered accordingly.