Ye and Chang (1997) concluded that primitive species have
undifferentiated peduncles and sessile flowers, and they suggested
based on these morphological characteristics that C. hongkongensis
and C. subintergra are the most primitive species. In the study here-
in, C. subintegra and the four species with which they clustered in
the dendrogram are located in between C. saluenensis and C. retic-