A revision of Clematis sect. Pseudanemone (Ranunculaceae)

Clematis sect. Pseudanemone is revised in this paper. Sixteen species, three subspecies, and two varieties are recognized. They are keyed, described, and illustrated in most cases, and classified into three series. Brief taxonomic history and geographical distribution of the section are given, and its systematic position and origin are discussed. According to the evolutionary trends of certain morphological characters Of leaves, sepals, and anthers, the Madagascan ser. Pimpinellifoliae is considered the primitive group, and the other two series, ser. Villosae and ser. Chrysocarpae, all occurring on the African mainland, the advanced groups.