In this work we brought together two rbcL datasets for Polystichum s.l. (including Cyrtomium and Cyrtomidictyum ), independently developed in Vermont and Japan. Our goal was to test earlier hypotheses based only on the Vermont analysis and to focus on the origin of the Himalayan Polystichum crinigerum (C.Chr.) Ching, whose generic assignment was unclear. The analysis of 60 taxa including three members of Phanerophlebia as the outgroup yielded 60 most parsimonious trees 264 steps long. The strict consensus of these trees revealed that six clades identified in an earlier analysis of 41 taxa were retained in this analysis of 57 taxa. These clades were the Cyrtomidictyum clade, the Cyrtomium clade, the Polystichum s.s. clade, and included in the last the tropical American clade, the African clade, and the apogamous clade. Six new clades were resolved. Prominent among these was a clade comprising all of the Sino-Himalayan taxa in the study set including Polystichum crinigerum . Another was a clade comprising five of eight Sino-Japanese species; two more formed a second clade. The identification of a newly resolved clade including only P. munitum and P. imbricans , which form partially fertile hybrids, adds to our confidence that our phylogeny is a good working hypothesis for the evolutionary history of Polystichum . The early history of Polystichum s.s. was still not resolved in this analysis, and seven species of this group, including all four austral species, were unassociated with others. In summary, the increase in the density of sampling of Asian taxa substantially improved the resolution of the phylogeny of the Asian Polystichum species and placed P. crinigerum as a derived member of a Sino-Himalayan lineage in the genus. The strong tendency for members of clades to be endemic to biogeographic regions suggests that evolution in Polystichum s.s. has largely been localized in these regions.

Key words: Asia, Dryopteridaceae, phylogeny, Polystichum, rbcL