A morphometric analysis of infraspecific taxa within the Ixeris chinensis complex (Asteraceae, Lactuceae)

Morphometric methods were used with 40 morphological characters from each of 110 individuals collected from 11 populations of the Ixeris chinensis complex to test hypotheses regarding infraspecific taxa. Individuals of the nearest relative I. tamagawaensis were included as an outgroup. To utilize structual associations of the original data and the cumulative values of character variation, a modified data set was generated by matching factor scores with the large original data set. As a result, the original data was reduced to about 10% of its original size. The modified data also emphasized the cumulative values of character variations. Structural associations among characters measured, however, were not significant for most factors extracted even though some obvious trends appeared. Relationships between cumlative values of variation and taxa in the complex are discussed based on the results of the canonical discriminant function analysis, ANOVA, multiple comparison test, and cluster analysis, using the modified data. This study supports Kitamura’s (1956) classification of infraspecific taxa in the I. chinensis complex. Given that there is no overlap of cumulative values of variation between the species complex and I. tamagawaensis, there is probably a 75% character overlap within the complex.