SUMMARYRhizoctoma isolates obtained from terrestrial orchids in South Australia and Great Britain have been induced to fruit in culture. The perfect states thus obtained belong to Thanatephortis cucitmeris (Frank) Donk, T. sterigmaticus (Bourdot) Talbot, T. orchidicola Warcup and Talbot, Ceratobasidiinn cornigerum (Bourdot) Rogers, C. obscurum Rogers, Ceratobasidium sp. indet., Tulasnella calospora (Boudier) Juel, T. asymmetrica sp. nov., Tulasnella sp. indet. and Sebacina lermifera Oberwinkler. Tulasnelta calospora was found to be the perfect state of three cultures considered to be Rhizoctonia repeiis Bernard. The status of the orchid-fungus association is discussed.

SUMMARYFurther Rhizoctonia isolates from Australian orchids have been induced to fruit in culture. The perfect states obtained include three new species of Ceratohasidium, C. angustisporum, C. globisporum, and C. papillatum, a new species of Tulasnella, T. irregularis, and a new species of Ypsilonidium Donk emend. Talbot, Y. anomalum Talbot.

Summary Further Rhizoctonia isolates obtained from Australian orchids have been induced to fruit in culture. The perfect states thus obtained include Tulasnella allantospora Wakefield and Pearson, T. violea (Quélet) Bourdot and Galzin, and two new species, T. cruciata and Ceratobasidium sphaerosporum. The description of Tulasnella asymmetrica is emended.

No abstract

Oncobasidium theobromae Talbot & Keane is described as a new genus and species of Basidiomycotina (Tulasnellales, Ceratobasidiaceae). This fungus occurs in the xylem and forms small corticioid fructifications on leaf-scars of cocoa (Theobroma cacao L.) showing dieback symptoms, in the Territory of Papua and New Guinea. Its affinities within the tulasnelioid fungi are discussed.