Abstract
Introduction: Phaseoleae is the third largest tribe in the family Fabaceae and is most diverse, with approximately 84 genera and 1500 species. It includes several economically and ecologically important species in the agricultural ecosystems, for example, major cover and cash crops such as Glycine max (L.) Merr (soybean), P. coccineus L. (scarlet or runner bean), P. lunatus L. (lima bean), P. vulgaris L. (common bean), Pisum sativum L. (pea), Vigna unguiculata (cowpea), V. radiata (mung bean) and Vicia faba L. (broad bean) and many other lesser-known crops used for food, fodder, ornamentals, and medicine. The Old World subtribe Phaseolinae in the tribe Phaseoleae is a taxonomically complex group represented in southern Africa by approximately 37 species distributed in eight genera, namely, Alistilus N.E.Br. (1), Decorsea R.Vig. (3) Dipogon Liebm. (1), Dolichos L. (9), Lablab Adans. (1), Macrotyloma (Wight & Arn.) Verdc. (6), Sphenostylis E. Mey. (2) and Vigna Savi (14). Aims: The study aims to infer intergeneric and infrageneric relationships between and within the genera currently placed in the subtribe Phaseolinae in southern Africa using morphological and molecular data and critically assess morphological characters traditionally used to delineate the genera and species within the subtribe Phaseolinae. This was done by arranging the specimens at a generic level using the morphology of the styles and to species level using the characters such as the stems, leaves and the fruits. Other useful diagnostic morphological characters for delimitation of genera and species within the subtribe were also identified. Furthermore, taxonomic revisions of two genera, namely, Alistilus and Decorsea, were undertaken. Methods: The inference was made by critically assessing morphological characters traditionally used to delineate the genera and species within the subtribe Phaseolinae...
M.Sc. (Botany)