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

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 .