Inonotus rwenzorianus (Basidiomycetes, Hymenochaetales) : an undescribed species from the Rwenzori Mountain range

Inonotus rwenzorianus (Basidiomycota, Hymenochaetales) is described as new from the Rwenzori Mountain range, in the Democratic Republic of Congo. The species is above all characterized by the combination of a thick, resupinate basidiomata, small pores, long extra-hymenial setae (setal hyphae) in the hymenophoral trama and the subiculum, abundant, variably shaped hymenial setae, and mostly ellipsoid, slightly thick-walled, very pale yellowish basidiospores. It is compared to I. pegleri, which is morphologically the closest species, also occurring in Africa. Its phylogenetic affinities are clearly within the Inonotus clade sensu Fischer and Wagner, but the relationships within this clade are, for the time being, still poorly resolved.