Remersonia, a new genus for Stilbella thermophila, a thermophilic mould from compost

Abstract

The thermophilic synnematous hyphomycete Stilbella thermophila is redescribed and illustrated based on the study of type and supplementary material. The species is transferred to a new anamorph genus, Remersonia, characterized by determinate synnemata with scarcely branched conidiophores, percurrently proliferating conidiogenous cells, relatively large ameroconidia that accumulate in slime, and thermotolerant growth. Cladistic analysis of partial 18S and 28S ribosomal DNA sequences suggest that the fungus is a member of the Sordariales. Septal ultrastructure and a failure to grow on benomyl-emended media support the ascomycetous affinities of the fungus. Failure to grow on cycloheximide-emended media supports sequencing data suggesting that the species is not allied with the Ophiostomatales. The biology of the fungus is briefly discussed. Key words: thermophilic fungi, mushroom compost, hyphomycetes, systematics, 18S rDNA, 28S rDNA.