A Taxonomic revision of the genus Vigna Savi (Fabaceae) in southern Africa

Abstract

Taxonomic investigation of Vigna Savi in southern Africa indicated the diagnostic importance of ridging of stems, pubescence type, stipule shape, presence or absence of heterophylly, extrafloral nectaries, structure of standard callosities and legume size/shape. Micromorphology focused on style prolongations, wing morphology and pollen sculpture. Taxa recognized: subgenus Vigna, with sections Vigna (V. luteola, V. marina, V. oblongifolia [varieties oblongifolia and parviflora]); Comosae ( V. comosa subsp. comosa var. comosa); Macrodontae ( V. friesiorum var. friesiorum); Reticulatae ( V. pygmaea) and Liebrechtsia ( V. frutescens subsp. frutescens var. frutescens); subgenus Catjang, with species, V. nervosa and V. unguiculata, the latter comprising subspp. protracta, stenophylla, dekindtiana (varieties dekindtiana and huillensis), tenuis (varieties tenuis and ovata); subgenus Haydonia, with sections Haydonia and Microspermae, comprising two undescribed species, V. mudenia and V. sp. nov. A.; subgenus Plectrotropis including sections Plectrotropis, with V. vexillata having new combinations varieties ovata and davyi (previously V. davyi), and section Pseudoliebrechtsia with V. lobatifolia.