Studies in Chaetosphaeria sensu lato I. The genera Chaetosphaerella and Tengiomyces gen. nov. of the Helminthosphaeriaceae

Species currently placed in Chaetosphaeria sensu late that have the charact er of transversely septate, versicoloured ascospores in common are discusse d in a series of publications. Revision of their type material revealed tha t they are not congeneric with the type species of Chaetosphaeria and with each other. The families Chaetosphaeriaceae, Helminthosphaeriaceae, Lasiosp haeriaceae and Trichosphaeriaceae are discussed. The present paper deals wi th species of the genus Chaetosphaerella with Oedemium and Veramycina synan amorphs, including material in the Czech Republic, China, Brazil, France, I ndia, Italy, Sri Lanka and U.S.A. Two species are accepted in Chaetosphaere lla, viz. C, fusca and C. phaeostroma. They are described and illustrated a nd listed along with their full synonymy and notes on previous descriptions and illustrations. A key to the species is provided. Chaetosphaerella fusi spora is excluded from the genus, its relationships with Chaetospfaerella a nd other genera are discussed. The new genus Tengiomyces is described for t he single species Tengiomyces indicus (syn. Chaetosphaerella indica), a lig nicolous, saprobic fungus. An associated hyphomycete, Spadicoides sp., is p resumed to be the anamorph. Additional species Chaetosphaeria bihyalina, C. incrustans, C. iquitosensis and C. phaeostromoides are considered and thei r relationships with Chaetosphaerella are disscused. On the basis of the mo rphological characters of perithecium, ascus and conidial development Chaet osphaerella and Tengiomyces are assigned to the Helminthosphaeriaceae.