Taxonomy and species diversity of Ganoderma species in the Garden Route National Park of South Africa inferred from morphology and multilocus phylogenies

<i>Ganoderma</i> is a cosmopolitan genus that encompasses species with cultural, economic, and pathogenic importance. Despite the importance of this genus, knowledge pertaining to the species diversity of <i>Ganoderma</i> in South Africa is limited. This study aimed at elucidating the identity and phylogenetic placements of <i>Ganoderma</i> samples obtained during a survey of wood-rotting fungi in the Garden Route National Park (GRNP) of South Africa, supplemented with isolates obtained from other localities across the country. Identification was achieved by means of multilocus phylogenetic inference combined with morphological evaluation. In total, eight distinct species of <i>Ganoderma</i> were recovered from different hosts and localities across the country. Of these, <i>Ganoderma</i> cf. <i>cupreum</i> and <i>Ganoderma</i> cf. <i>resinaceum</i> represent possible new records for South Africa. Two novel species are described, namely, <i>G. eickeri</i>. and <i>G. knysnamense. Ganoderma eickeri</i>, sp. nov., is characterized by a triquetrous and broadly attached basidiome, a sulcate or zonate yellowish brown to brown pilear surface, and ovoid to ellipsoid basidiospores. <i>Ganoderma knysnamense</i> is distinguished by an applanate to ungulate, sometimes convex, dimidiate to broadly attached basidiome, a chocolate-brown pilear surface covered with a hard woody-like crust and ellipsoid, broadly ellipsoid to ovoid basidiospores. The discovery of two new <i>Ganoderma</i> species in this study raises the known <i>Ganoderma</i> species in South Africa to 13.