Two new African siblings of Pulveroboletus ravenelii (Boletaceae)

This paper sorts out the taxonomy of species affiliated with Pulveroboletus ravenelii in the Guineo-soudanian and Zambezian woodlands of Africa. Morphological and genetic characters of African Pulveroboletus collections were studied and compared to those of North American and Asian species. A phylogenetic analysis showed that the African specimens form a subclade, sister to the Asian and American taxa. Although clamp connections have previously never been reported from Pulveroboletus, all specimens of the African subclade show very small clamp connections. Two new African species, Pulveroboletus africanus sp. nov. and P. sokponianus sp. nov., are described and illustrated. Comments concerning morphology and identification, as well as distribution and ecology, are given for both species.