||Daphniphyllaceae is a monogeneric family with a main distributional range from tropical to subtropical South East or East Asia. Totally, Daphniphyllum consists of about 30 species in the world. Only a few morphological characters can be used because of the reduced reproductive organs and the variable leaves, which has led to difficulties in intrageneric classification and species identification. To find out more good and diagnostic characters for the delineation of species in the family becomes important and necessary. |
The dispute concerning the phylogeny of the family is always present since it was established. The families Euphorbiaceae, Buxaceae, Pittosporaceae, Hamamelidaceae, Cercidiphyllaceae, Paeoniaceae and Peridiscaceae have been separately considered as most closely related family by many authors. The characters which the authors used for analysis included floral structure, pollen morphology, wood anatomy and DNA sequence. However, those micro-morphologies of leaf anatomy and epidermal characteristics which may provide detailed information have been seldom evidenced. This study attempts to utilize the molecular evidences (nrITS, psbA-trnH spacer, trnL intron of chloroplast DNA) for phylogenetic analysis and to evaluate the comparative morphological characters of leaves in identification of species for taxonomy.
The results of molecular analysis reveal that Daphniphyllaceae is monophyletic and close relationship with Cercidiphyllaceae or Hamamelidaceae. The phylogenetic relationship among the species and the sister group of Daphniphyllaceac have not yet been resolved. The results of morphology and anatomy show that the main characters for taxonomy were female flowers and leaf venation. The features of leaf epidermis, fruit or leaf scar are helpful in distinguishing taxa. Totally, 28 species and 4 varieties are here recognized in the genus.