The principal aim of this study was to establish biogeographical patterns in the legume flora of southern
Africa so as to facilitate the selection of species with agricultural potential. Plant collection data from the
National Herbarium, South Africa, were analysed to establish the diversity and areas covered by legumes
(Leguminosae/Fabaceae) indigenous to South Africa, Lesotho and Swaziland. A total of 27,322 records
from 1,619 quarter degree grid cells, representing 1,580 species, 122 genera and 24 tribes were included
in the analyses. Agglomerative hierarchical clustering was applied to the presence or absence of legume
species in quarter degree grid cells, the resultant natural biogeographical regions (choria) being referred
to as leguminochoria. The description of the 16 uniquely formed leguminochoria focuses on defining
the associated bioregions and biomes, as well as on the key climate and soil properties. Legume species
with a high occurrence in a leguminochorion are listed as key species. The dominant growth form of key
species, species richness and range within each leguminochorion is discussed. Floristic links between the
leguminochoria are established, by examining and comparing key species common to clusters, using a
vegetation classification program. Soil pH and mean annual minimum temperature were found to be the main drivers for distinguishing among legume assemblages. This is the first time that distribution data for
legumes has been used to identify biogeographical areas covered by leguminochoria on the subcontinent.
One potential application of the results of this study is to assist in the selection of legumes for pasture
breeding and soil conservation programs, especially in arid and semi-arid environments.
This paper is dedicated to the memory of Robert Howard (Bobby) Westfall
(17 December 1944–21 January 2016), vegetation ecologist and friend
whose sudden death during the preparation of this manuscript deprived
us of an invaluable collaborator.