Hymenasplenium was recognized as a genus in the present generic delimitation of the family Aspleniaceae. It is a well-defined group with unusual dorsiventral vascular system in long creeping rhizomes and chromosome base numbers differing from typical of Asplenium of x=36. Members of Hymenasplenium are widely distributed in the tropic zones of the world. Southwestern China is the place with the highest diversity of Hymenasplenium species. Moreover, cytologically and reproductively abundant basal forms of Hymenasplenium exist in Southwestern China supporting the assumption that this region is a ...