Morphological variation of inflorescence paraclades of Ainsliaea latifolia and taxonomic status of A. latifolia var. ramifera
GAO Tian-Gang (State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China)
The paraclade of the inflorescence of Ainsliaea latifolia was usually described as a cluster of one or 2–4 capitula without indicating its morphological nature. Extensive field and herbarium observations were conducted to examine the morphological nature and variation of paraclades in populations of A. latifolia. Three types of inflorescences can be distinguished according to the condition of reduction and condensation of the paraclades, which are simple compound cyme, complex compound cyme and the transitional type. Individuals with the last two types are rare in populations. This finding provides new insights into evolution of the various kinds of inflorescences in the genus, as well as taxonomy of this widely distributed species. The apexes of whole inflorescence axes of some individuals with complex compound cymes are broken, caused by insect eating or other external forces. It is noteworthy that the holotype of A. latifolia var. ramifera exhibits this phenomenon. Therefore A. latifolia var. ramifera is reduced to synonymy with the typical variety, as no other apparent difference in distribution, habitat and phenology is found between them.