A revision of Clematis sect. Aspidanthera s. l. (Ranunculaceae)

In this paper Clematis sect. Aspidarahera s. 1. is revised. Seventy-two species and 15 varieties are recognized. They are keyed, described, and in most cases illustrated, and are classified into six subsections. Of them, one series, five species, and two varieties are described as new, and two new ranks are proposed. Brief taxonomic history and geographical distribution of the section are given, the evolutionary trends of several important morphological characters observed are enumerated, and the relationships of its subsections are discussed. As a result, subsect. Dioicae, which shows striking resemblance in both habit and floral structure to sect. Clematis subsect. Clematis, is regarded as the primitive group, while subsect. Insidiosae, bearing pistillate flower with erect sepals and no staminodes, is regarded as the advanced group within the section.