No abstract

Three new species of Amanita, section Vaginatae , are described from Tanzania: A. tanzanica Hii.rk. & Saarim., A. masasiensis Hii.rk. & Saarim. and A. mafingensis Hii.rk. & Saarim. These species are related to A. hemibapha (Berk. & Br.) Sacc., the tropical relative of A. caesarea (Scop. : Fr.) Pers. All the new species are considered edible by the local people and have a collective vernacular name in each tribe. They are often confused with the poisonous A. muscaria (L.: Fr.) Pers., which is abundant in exotic pine plantations, and mushroom poisonings, even fatal ones, occur.

A brief introduction of the project on Tanzanian edible mushroom is given along with the main features of the soil and vegetation of the collecting sites. The importance of Russulaceae in Africa and the collected Russula species are discussed. Thirty-six specimens of Russula were collected between 1989-1991, and of this material, 21 species of Russula were identified. Nineteen species are reported from Tanzania for the first time. R. tenuithrix Buyck sp. nov., R. tanzaniae Buyck sp. nov., R. hiemisilvae Buyck sp. nov., R. sublaevis (Buyck)Buyck stat. nov. and nine other species were found in woodlands, R. usambarae Buyck sp. nov., R. acriannulata Buyck sp. nov. and five other Russula in lower montane forest. One species has been introduced in Pinus plantations. Along with a key to the collected Russula species, their systematic position, distribution and possible host trees are discussed and compared with earlier data from Tanzania and other African countries. A discussion on the edibility of Russula is also included.

Ten species of Gasteromycetes (Basidiomycotina) collected in Tanzania are described or mentioned in this article. Phallus tenuis (E. Fisch.) Kuntze seems to represent the first record for Africa.

Myxomycetes were more abundant in the montane forest belt than at other elevations, and no significant difference could be noticed in species composition between the two rainy seasons, May and December. Species belonging to the order Licheales were found only on decaying wood, and of the Physarales the majority of the specimens were found on litter.