1) The chromosome numbers and karyotypes were studied in seven species of Cynareae and one species of Arnica. 2) The chromosome numbers of Cephalanoplos setosum, Cirsium tashiroi, C. lineare and Saussurea tanakae are here reported for the first time. 3) A close phylogenic relationship between the genus Cephalanoplos and the genus Cirsium is suggested from the karyotypical viewpoint. 4) The karyological difference between Saussurea and Cirsium was found from their chromosome morphologies. 5) The basic chromosome numbers of the genera belonging to Tribe Cynareae were discussed. 6) Hemistepta lyrata, Carduus crispus have characteristic karyotypes different from all the rest of Tribe Cynareae.
The prophyll position of Xanthium canadense was statistically studied. The first leaf (prophyll α) of the vegetative lateral branch is mostly anodic in position, but that of the reproductive branch which terminates in staminate or pistillate heads is less frequently anodic (Fig. 1B). Moreover, the frequent occurrence of cathodic prophyll is found in lateral branches which belong to certain basal nodes of a main stem or of a lateral branch (Table 1, Fig. 1A). For analysis of the factors which induce the frequency variation of cathodic prophyll, the divergence angle and the internode length were examined (Table 2, Fig. 2). Lateral branches are divided into two types-abaxial and adaxial types-in respect of their third leaf (prophyll γ) position (Fig. 5A). Although the abaxial type is usual, primary branches from lower nodes of a main stem are frequently of the adaxial type (Table 3, Fig. 4). Primary branches of these two types are different from each other not only in the divergence angle and the internode length, but also in the frequency curve of cathodic prophyll which belongs to the secondary branch (Table 4, Fig. 4, Table 5, Fig. 5). One pistillate head develops into a couple of seeds-an adaxial smaller seed and an abaxial seed. The plants germinated from the adaxial seeds and those from the abaxial ones are different from each other in the basal frequency curve of cathodic prophyll on the primary branch and also in that of the primary branch whose third leaf is adaxial (Fig. 6).