Notes on hyphomycetes. LXXIX. Concerning the Acladium-Alysidium-Haplotrichum complex; Nomenclatural and taxonomic considerations, with redescriptionsof respective type species

The generic name Haplotrichum is maintained for anamorphs of Botryobasidium on the basis of its having been sanctioned by Fries, although Acladium, wh ich is considered a synonym, was published some fifteen years earlier. Alys idium is also regarded as being synonymous, in accordance with the genus-fo r-genus philosophy, although its type species differs somewhat morphologica lly from that of Haplotrichum. The species on which the three generic names are based are redescribed and illustrated in order to more clearly define the unified generic concept. A comprehensive description of the genus chara cteristics is also provided. The recombined binomial Haplotrichum dubium [e quivalent to Trichoderma dubium] is adopted for the anamorph of Botryobasid ium aureum because of the date priority of its basionym.