Lu An-Ming, Zhang Zhi-Yun
1985, 23 (2): 106–120
The classical and numerical taxonomy, palynology and the geographical distribution of the Genus Schizopepon are dealt with in the present paper. Having commented on various opinions regarding the systematic position of the genus, the present authors consider that C. Jeffrey’s treatment of Schizopepon as a new and monogeneric tribe, Schizopeponeae, should be supported.
The gross morphological characters in the genus are assessed from the taxonomic
point of view. Some characters, such as stamens with an elongated connective or not,
different insertions of ovules and various forms of ovaries and fruits, may be used for
The pollen grains of all the species were observed under light microscope (LM) and
scanning electron microscope (SEM). The results show that a strong differentiation
has taken place in the pollen of the genus, and in consequence it may be regarded as an
important basis for dividing subgenera and species. Especially it should be pointed out
that degrees of development of colpi and positions of ora are positively correlated with
the external characters used for distinguishing subgenera.
According to the morphological and palynological characters, the genus Schizopepon
may be divided into three subgenera and eight species: 1. Subgenus Schizopepon: 5 species, S. bryoniaefolius Maxim., S. monoicus A. M. Lu et Z. Y. Zhang, S. dioicus Cogn.,
S. longipes Gagnep. and S. macranthus Hand.-Mazz.; 2. Subgenus Rhynchocarpos A. M.
Lu et Z. Y. Zhang: 1 species, S. bomiensis A. M. Lu et Z. Y. Zhang; 3. Subgenus Neoschizopepon A. M. Lu et Z. Y. Zhang: 2 species, S. bicirrhosus (C. B. Clarke) C. Jeffrey
and S. xizangensis A. M. Lu et Z. Y. Zhang.
The 8 OTU’s including all the species of this genus and 31 characters, of which 16 are morphological characters and 15 palynological characters, were used in the numerical taxonomic treatment. After standardization of characters, the correlation and distance matrices were computed. The correlation matrices are made to test the various clustering methods. At last, the UPGMA clustering method was selected and its result
is shown in the form of phenogram. The result of numerical analysis is similar to that of the classical classification.
Schizopepon Maxim. is a genus of East Asia-Himalayan distribution. China has all 8 species and 2 varieties, of which 6 species are endemic. Based on the statistics of spedies number, the distribution centre of the genus is considered to be in the Hengduan Mountains (Yangtze-Mekong-Salwin water divides) and the adjacent areas of the southwest China.