Taxonomic revision and cladistic analysis of Diphyscium (Family Diphysciaceae) of Taiwan

Six species of Diphyscium, with three new additions to the moss flora of Ta iwan, are revised taxonomically, including D. chiapense Norris ssp. unipapi llosum (Deguchi) T. Y. Chiang and S. H. Lin, stat. nov. Diagnosable keys ar e provided. In order to test Norris' and Deguchi et al.'s classifications, cladistic analyses were carried out on eleven morphological traits scored f rom nine Asiatic species of Diphyscium. Two equally parsimonious trees root ed at the Theriotia species were recovered by PAUP. The reconstructed phylo geny, which suggested a close relationship between the taxa with single pap illose lamina cells and the species with pluripapillose lamina cells, inval idated Norris' hypothesis. The parsimony tree agrees with Deguchi et al.'s classification, in which three groups were classified based on cell-wall pa pillosity. Based on the inferred phylogeny, the "orifice" stomata may have evolved more than once in Diphyscium, while a single "secondary loss" event occurred in the group of D. involutum, D. rupestre, D. mucronifolium and D . suzukii.