Polystichum jinpingense (subg. Haplopolystichum; Dryopteridaceae), a new fern from southeastern Yunnan, China

A new fern species, Polystichum jinpingense, a member of P. subg. Haplopolystichum sect. Haplopolystichum, is described and illustrated from southeastern Yunnan, China. Polystichum jinpingense is most similar to P. subacutidens in plant size and having numerous pinnae, but the former has thinner (0.7–0.9 mm in diam.) rachis, oblong pinnae, pinna margins undulate, and pinna apex cuspidate, whereas the latter has thicker (1.1–1.4 mm in diam.) rachis, triangular pinnae, pinna margins serrate, and pinna apex acuminate. Polystichum jinpingense has an extremely narrow distribution and is classified as Critically Endangered (CR) following IUCN Red List Criteria.