Vigna

Cowpeas

Scientific classification

Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Fabales
Family:	Fabaceae
Subfamily:	Faboideae
Genus:	*Vigna* Savi

Species

see text

The cowpeas are the genus Vigna in the plant family Fabaceae. They include some well-known and not so well known bean species formerly included in the genus Phaseolus.

ITIS accepts 20 species, some of them with several subspecies. Many of them have common names including the word "cowpea". Used on its own, however, "cowpea" refers either to the genus as a whole or to the black-eyed pea Vigna unguiculata ssp. dekindtiana.

Many references even in current literature will place some of these species in genus Phaseolus. According to Hortus Third, however, Vigna differs from Phaseolus in that

plants in Vigna often have stipules that are appendaged
the thickened part of the style is less strongly twisted
details of the pollen
details of the biochemistry

Examples of Vigna species include:

V. acontifolia moth bean
V. angularis azuki or adzuki bean
V. mungo urd bean or urd
V. radiata mung bean, green gram
V. subterranea Bambara groundnut (placed by some authors in genus Voandzeia)
V. umbellata rice bean
V. unguiculata cow bean
- V. unguiculata ssp. cylindrica Catjang
- V. unguiculata ssp. dekindtiana Black-eyed pea
- V. unguiculata ssp. sesquipedalis Yardlong bean
- V. unguiculata ssp. unguiculata Southern pea
V. vexillata zombi pea