Volvariella acystidiata (Agaricomycetes, Pluteaceae), an African species new to Europe, with two new combinations in Volvariella

Volvariella acystidiata, an African species belonging to the V. gloiocephala-complex, is firstly reported from Europe on the basis of a collection made in northern Sardinia. This species is easily recognized by its medium size, white overall colour, large, ellipsoid to ovoid basidiospores and the lack of cystidia of any kind. The study includes a description, a photograph of fresh basidiomes and line drawings of relevant microanatomic traits.