This month Mycological Research News features the role of pathogenic Pythium species in the control of patterns of tree distribution in forests, unravelling the relationships of Rhizoctonia-like fungi, and homothallism in apotheciate lichens.

Amongst the 19 papers in this issue are molecular studies on Leptosphaeria maculans, Fusarium solani and Mortierella alpina. Two isozyme groups are reported within F. graminearum, the xylanases in Agaricus bisporus cultures are compared, and the enzymes of white-rot fungi studied. Effects of heavy metals on ericoid mycorrhizas, and the soluble carbohydrates in Pinus ectomycorrhizas have been analyzed. New data are presented on osmotic pressures and osmolytes, and the factors affecting branching in Neurospora. The endophytes of Rubus, and xylem degradation by Fistulina hepatica are explored. Plant pathological contributions include ones on karyotypes in Pyrenophora, Gibberella and Fusarium on teosinte and maize, and Aphanomyces on peas.

Revisions of Hygrocybe subgen. Hygrocybe in the Greater Antilles, and Harknessia species on Eucalyptus are reported, a new synnematal hyphomycete genus is described, and new species of Corynascus have been discovered.

The following new scientific names are introduced: Siamia gen. nov.; Corynascus sexualis, C. similis, C. verrucosus, Harknessia tasmaniensis, Hygrocybe chimaeroderma and S. luxuriosa spp. nov.; H. calyptriformis var. domingensis and H. konradii var. antillana vars. nov.; H. acutoconica var. microspora (syn. Hygrophorus acutoconicus var. microsporus), H. conica var. brevispora (syn. Hygrophorus nigrescens var. brevisporus), H. luteistipes (syn. Hygrophrus luteistipes) combs. nov.