Polystichum suiyangense (sect. Sphaenopolystichum, Dryopteridaceae), a new fern from Guizhou, China

Polystichum suiyangense (Dryopteridaceae), a new species from Suiyang County, Guizhou, China, is described and illustrated. It is a member of P. sect. Sphaenopolystichum and similar to P. auriculum, P. bifidum, and P. martinii, but differs from them in its frond texture, leaf color, scales on petiole and rachis, pinna shape, and pinna apex. The new species is currently known only from the type locality and is classified as CR (critically endangered) following the IUCN criteria.