A Taxonomic Revision of the Woody South African Genus Notobubon (Apiaceae: Apioideae)

Abstract

A comprehensive taxonomic revision of the genus Notobubon (Apiaceae) is presented. Twelve woody evergreen species are recognised, all (with the exception of N. laevigatum) endemic to the Cape Floristic Region of South Africa. The taxonomy of these prominent, though poorly collected, species has until now been problematic. They are distinguished from one another by their habit (size and branching pattern), the overall shape, size, and colour of the ultimate leaflet segments, the inflorescence structure (peduncle length, number, and length of rays in the primary umbel), the fruit morphology (fruit size, presence or absence of wings), and the fruit anatomy (symmetry of the mericarps, presence or absence of additional rib vittae, size of commissural vittae). Species relationships are assessed in the form of a cladistic analysis of 26 morphological characters, resulting in a well-resolved phylogenetic hypothesis. A comprehensive key to the species, their correct nomenclature, and typification, together with descriptions and known geographical distribution for all the species are presented and illustrated.