Vigna unguiculata belongs to the Fabaceae, a family known for its economic and cultural importance due to diverse edible vegetables, medicinal uses and nitrogen-fixing ability, reducing fertilizer costs. Fabaceae includes trees, shrubs and herbaceous plants, recognized by legumes and compound leaves. It is the third-largest plant family, with 765 genera and nearly 20 000 species worldwide.

The genus Vigna is named after Domenico Vigna, an Italian botanist who lived in the 1600s and worked as a professor and Director of the Botanical Garden in Pisa. The species name unguiculata is Latin for ‘with a small claw’, describing the tiny stalks found on the flower petals.

The genus Vigna includes about 150 species, mostly found in tropical regions worldwide, with the highest diversity in Sub-Saharan Africa. South Africa is home to about 16 species of Vigna. Among these, cowpea (Vigna unguiculata) stands out as a unique and complex crop, with many subspecies and wild relatives, all primarily originating from Africa. Over time, scientists have reclassified cowpea, grouping it under Vigna unguiculata subspecies unguiculata, which includes four main types (cultigroups). Modern tools like DNA markers have helped researchers better understand cowpea's origins, diversity, and relationships. Cowpea is believed to have originated in Sub-Saharan Africa, where wild varieties are still found today. Earlier theories suggested that cowpea had two separate origins, one in Africa and another in Asia. However, this idea has been dismissed because wild cowpeas do not exist in Asia. Cowpea's domestication began around 6 000 years ago when West African farmers cultivated it alongside pearl millet and sorghum.

The crop is thought to have been brought to South Africa around 1 600 years ago by Nguni-speaking communities. Along with cowpea, they introduced farming tools and skills like ironworking and pottery, which made it easier to store and manage harvested crops effectively. These communities also brought farming tools and knowledge of ironworking and pottery, helping them store and use harvested crops effectively. Today, cowpea is grown across Africa, Latin America, Southeast Asia, and parts of the southern United States. It is valued as a source of food, animal feed and vegetables. Despite its importance, wild cowpeas are sometimes confused with closely related plants like the wild sweetpea (Vigna vexillata). Adding to the challenge is the existence of over 700 cultivated varieties worldwide. In South Africa, cowpea is no longer widely grown because European bean varieties have largely replaced it in commercial farming. This shift has caused cowpea to become less common in rural areas, where it was once a staple crop.