The genus Polyporus (Polyporales, Basidiomycota) with a focus on neotropical species with black stipes.

The generic limits of Polyporus have remained unstable and poorly justified despite recent phylogenetic studies. In the present paper, we address this problem by investigating the taxonomy of 43 Neotropical Polyporus species (Polyporaceae, Polyporales), with a primary focus on 32 species with a black stipe (the so-called melanopodous species). Based on a three-gene (ITS + LSU + RPB1) phylogeny of the Polyporaceae (including 94 species), we argue for keeping all melanopodous Polyporus spp. within a single redefined genus, Polyporus, and discuss three alternative reclassification approaches for the genus. As re-established here, Polyporus forms a strongly supported clade sister to Mariorajchenbergia and the Favolus / Neofavolus group. We further revise the taxonomy of the P. leprieurii - guianensis group (with 12 accepted Neotropical species), P. blanchetianus complex (nine Neotropical species), P. diabolicus complex (six Neotropical species), and P. melanopus complex (five Neotropical species), based on ITS and, in the case of P. blanchetianus group, also TEF1 markers. This revision is supplemented by thorough type studies of existing taxa. Eight melanopodous Neotropical species are described as new. Additionally, nine other Neotropical Polyporus spp., with pale stipes or sessile basidiocarps, are reinstated, and three more are described as new to science. Available ITS sequences point to a higher species diversity in P. leprieurii - guianensis, P. blanchetianus and Echinochaete groups than currently recognized. The identity of five extraneous melanopodous species is addressed, and 25 species are treated under excluded or insufficiently known taxa. Our results demonstrate that current splitting schemes of Polyporus s. lat. are difficult to justify and instead support a redefined, more inclusive concept of the genus. Taxonomic novelties: New species: Polyporus atrocinctus Vlasák & Runnel, Polyporus corniculum Vlasák & Spirin, Polyporus crassitectus Vlasák & Spirin, Polyporus ferropus Vlasák & Spirin, Polyporus lineolatus Vlasák & Spirin, Polyporus obfuscatus Vlasák & Spirin, Polyporus palmiceps Vlasák & Spirin, Polyporus phaeostomus Vlasák & Spirin, Polyporus spondylus Vlasák & Spirin, Polyporus striifer Vlasák & Spirin, Polyporus vastulus Vlasák & Spirin. New combinations: Polyporus puiggarii (Speg.) Vlasák & Spirin, Polyporus taxodii (Murrill) Spirin & Vlasák. Lectotypes (basionyms): Polyporus bathyporus Rostk., Polyporus nephelodes Lév., Polyporus vadosus Lloyd. Citation: Spirin V, Vlasák J, Niemelä T, Runnel K (2026). The genus Polyporus (Polyporales, Basidiomycota) with a focus on neotropical species with black stipes. Studies in Mycology 114: 487-553. doi: 10.3114/sim.2026.114.04.