Polystichum normale (Dryopteridaceae), a new species in section Crucifilix from Guizhou, China

Abstract

A new fern species, Polystichum normale Ching ex P. S. Wang & Li Bing Zhang (Dryopteridaceae), is described from Guizhou and illustrated for section Crucifilix Tagawa. Distributed in southern Chongqing, northeastern and southeastern Guizhou, and northwestern Hunan, China, the new species is morphologically similar to P. tripteron (Kunze) C. Presl and P. hancockii (Hance) Diels. Polystichum normale has toothed and oblong or almost rectangular pinnae with an acute apex. In contrast, P. tripteron has coarsely serrate and falcate-lanceolate pinnae with an acuminate apex. While P. normale has sori close to the pinna margins, indusia 0.6-0.8 mm in diameter, and a perispore with an irregularly perforate sculpture, P. hancockii has sori closer to the costa, indusia 0.3-0.4 mm in diameter, and a perispore with reticulate sculpture. It is considered Vulnerable (VU), based on IUCN Red List criteria.