ANALYSES ON THE CHARACTERS OF THE GENUS OTTELIA (HYDROCHARITACEAE) IN CHINA

The present paper made a R cluster analysis and a Principal component analysis (PCA)on the 84 characters including morphotogical, biological and ecological ones of all the taxa of Ottelia so far known from China, R cluster analysis results showed thaa the characters studied could be obviously divided into several highly-related character groups which either suggested the genus tends to become secondarily terrestrial and highly cross-pollinated or were of great taxonomic importance, The results through PCA revealed that, ① only the first sixteen principal components comprise almost total information amount possessed by 84 characters, which indicates that the characters selected for classifying Chinese Ottelia are quite reasonable, and ② merely the first three principal components accounts for 76.56% information amount of that possessed by all characters, which further means that in a tri-dimensional space the relative position among all the taxa of Chinese Ottelia could be depictured successfully.