Hymenaspleniumtholiformis (Aspleniaceae), a new fern species from southeastern Xizang, China based on morphological and molecular evidence.

Abstract

A new species of Aspleniaceae, Hymenaspleniumtholiformis sp. nov., is described from Medog County in southeastern Xizang, China. The new species is morphologically similar to H.apogamum and H.szechuanense, but the former has ascending pinnae, pinna apex obtuse to rounded, pinna-marginal teeth entire, and veins terminating just below marginal teeth. Phylogenetic analysis based on five plastid markers confirmed that this new species represents a diverging lineage in the H.excisum subclade of Hymenasplenium.