New species of Hohenbuehelia, with comments on the Hohenbuehelia atrocoerulea - Nematoctonus robustus species complex.

Four new species of Hohenbuehelia (Fungi: Pleurotaceae) are described in the group of Hohenbuehelia atrocoerulea and Hohenbuehelia grisea. Hohenbuehelia algonquinensis, found on Pinus in Ontario, Canada, may be distinguished macroscopically from bluish collections of H. atrocoerulea and watery grey-brown collections of H. grisea by its coal-black pileus. Hohenbuehelia canadensis, on or associated with Pinus in both Ontario and Alberta, Canada, and Hohenbuehelia nimueae, on Salix in Ontario and Abies in Wyoming, USA, have similarly dark fruiting bodies and were previously misidentified as H. approximans (which we treat as a synonym of H. grisea), H. atrocoerulea, H. mustialensis or H. nigra. The latter species is shown to be a member of Resupinatus, despite the presence of prominent metuloid cystidia in its hymenium. Hohenbuehelia carlothornii has been found in Costa Rica; collections of the sexual fruiting bodies were previously identified as H. grisea and isolates from soil nematodes were identified by the anamorph name Nematoctonus robustus. That name has been treated as a synonym of H. atrocoerulea but, given the genetic and geographic variation within this complex, we transfer it to Hohenbuehelia as a distinct species. Sequences of the nuclear ribosomal DNA internal transcribed spacer region (ITS), the D1/D2 variable region of the large subunit gene, and a portion of the translation elongation factor (TEF1) gene provide good separation and support for these new species. A key to the dimidiate species of Hohenbuehelia of North America and Europe is provided.

Molecular systematics of the cotton root rot pathogen, Phymatotrichopsis omnivora.

Cotton root rot is an important soilborne disease of cotton and numerous dicot plants in the south-western United States and Mexico. The causal organism, Phymatotrichopsis omnivora (= Phymatotrichum omnivorum), is known only as an asexual, holoanamorphic (mitosporic) fungus, and produces conidia resembling those of Botrytis. Although the corticoid basidiomycetes Phanerochaete omnivora (Polyporales) and Sistotrema brinkmannii (Cantharellales; both Agaricomycetes) have been suggested as teleomorphs of Phymatotrichopsis omnivora, phylogenetic analyses of nuclear small- and large-subunit ribosomal DNA and subunit 2 of RNA polymerase II from multiple isolates indicate that it is neither a basidiomycete nor closely related to other species of Botrytis (Sclerotiniaceae, Leotiomycetes). Phymatotrichopsis omnivora is a member of the family Rhizinaceae, Pezizales (Ascomycota: Pezizomycetes) allied to Psilopezia and Rhizina.

Isolation of saprophytic basidiomycetes from soil.

A method with the combined advantages of soil particle washing, selective inhibitors, and an indicator substrate was developed to isolate saprophytic basidiomycetes from soil. Organic particles were washed from soil and plated on a medium containing lignin, guaiacol, and benomyl, which reduced mold growth and allowed detection of basidiomycetes producing laccase or peroxidase. The 64 soil samples yielded 67 basidiomycete isolates, representing 51 groups on the basis of morphology and physiology. This method should facilitate investigations into the biodiversity of soil basidiomycetes and yield organisms that are useful in bioremediation of soils contaminated with pesticides or other recalcitrant aromatic compounds.

Unusual presentation of metastatic carcinoma of prostate.

An unusual case of metastatic carcinoma of prostate, which presented as a huge abdominal mass and responded extremely well to endocrine therapy, is presented. The literature is reviewed.

Carnivorous mushrooms.

Ten species of gilled fungi, including the oyster mushroom (Pleurotus ostreatus), have been shown to attack and consume nematodes. It is suggested that these wood-decay fungi utilize the nutrients in their prey to supplement the low levels of nitrogen available in wood. This mode of nutrition is similar in principle to that of carnivorous higher plants.