Ophiostoma setosum, a common sapwood staining fungus from western North America, a new species of the Ophiostoma piceae complex

Ophiostoma setosum is described as a new species commonly associated with e xposed sapwood of Tsuga heterophylla in western North America. If is charac terized by the production of a typical ophiostomatoid teleomorph, a Pesotum anamorph with conspicuous, dark seta-like hyphae on the synnema stipes and apices, and a Sporothrix mycelial anamorph with solitary or short-catenate conidia. Mating experiments demonstrate that the species has two mating ty pes controlled by two alleles at a single locus and is reproductively isola ted from similar biological species of the O. piceae complex. Phylogenetic analysis of DNA sequences from the ITS2 and 5' end of the large nuclear sub unit (26S) of the ribosomal DNA supports the close relationship of O. setos um and O. piceae.