Molecular Phylogeny of the Lady Fern Genus Athyrium in Japan Based on Chloroplast rbcL and trnL-trnF Sequences
Phylogenetic relationships in Athyrium and Cornopteris were deduced from two chloroplast DNA fragments, rbcL and trnL 5'exon-trnF, of 32 species, 2 varieties, 3 putative hybrids of Athyrium, three taxa of Cornopteris, and five outgroups. Athyrium is paraphyletic, and the Athyrium-Cornopteris complex comprises five clades. Clade I, the most basal, comprises A. niponicum, A. (=Anisocampium) sheareri, and A. (=Kuniwatsukia) cuspidatum. Clade II includes A. distentifolium and Cornopteris. All species of clades III and IV are diploids, while most species of Glade V are polyploids. The parentage of the putative hybrids and of species of hybrid origin were also suggested. The results were compared to previous major classifications based on morphology.