A taxonomic revision of the genus Nanobubon (Apiaceae: Apioideae)

Nanobubon is a recently described genus consisting of two evergreen, perennial suffrutices endemic to the Cape Floristic Region of South Africa. Nanobubon strictum (Spreng.) Magee and N. capillaceum (Thunb.) Magee share a partly sympatric distribution, from the Cape Peninsula northwards to the Cedarberg mountains and eastwards to Port Elizabeth. Although both species are relatively similar in their highly sclerified and much-divided evergreen leaves with sub-terete ultimate segments, they can be distinguished from one another by the orientation of the leaves (erect or reclining), the branching pattern of the leaves (pinnae erect or spreading), the curvature of the leaf rachises and segments (straight or refracted), the colour of the flowers (yellow or cream-coloured) and the prominence of the dorsal ribs on the fruits (prominent or inconspicuous). The nomenclature and typifications, as well as complete descriptions and known geographical distributions are presented.