Cowpea in generalThe genus of the cowpea, Vigna, is a relatively large pan-tropical genus, with the majority of its species being found in Africa.
All species have 22 chromosomes, with little cryptogenic divergence. Vigna unguiculata includes the annual cowpeas and ten wild perennial subspecies. The closest wild subspecies to cowpea are pubescens, tenuis and alba.
There is conflicting evidence on where the crop was first domesticated, probably due to the considerable amount of hybridization that had occurred between cultivated and wild races. In the most comprehensive molecular survey of wild populations, the cultivated of ssp, unguiculata var. spontanea, although enough variability exists for other locations not to be excluded.
Regardless of its precise origin, Cowpea was probably cultivated by 7000 to 6000 BC and arrived in India about 4000 years ago with the grain species.
Considerable divergence occurred in chickpea soon after its cultivation began. It is believed that cowpea was used as a fodder crop for cattle prior to domestication for human consumption. The original forms were probably spreading, short-day plants that readily scattered their seeds.
Pod dehiscence and seed dormancy were most probably lost quickly in conjunction with domestication. Upright, day-neutral types may have first emerged after introgression with local wild relatives in the rain forest of Africa.
The fodder and green pod vegetable were probably developed after the crop arrived in Asia.
Cowpea in general
Read further: History of Cowpea
