Vigna unguiculata



Vigna unguiculata

(L.) Walp. 1843

pronounced: VIG-nuh un-gwee-kew-LAH-tuh

(Fabaceae — the pea family)

subfamily: Faboideae - the bean subfamily

common name: cowpea

Vigna was named for Dominico Vigna, an Italian botanist during the first half of the 17th century, who was Professor of Botany and Director of the botanical garden at Pisa, and wrote a commentary on the works of Theophrastus. Unguiculata is from the Latin unguiculatus, like a fingernail.

Vigna is broadly divided into 3 types, according to use: for grain, forage, or dual-purpose. Vigna unguiculata falls into the last type. There is a great deal of variation within the species, and there are many cultivars. It may be prostrate, climbing, or semi-erect to erect (15 – 80 cm high). The leaves are alternate, trifoliate, with petioles 5 – 25 cm long. The lateral leaflets are opposite and asymmetrical, while the central leaflet is symmetrical and ovate.

The inflorescence is racemose, and the flowers may be white, cream, yellow, mauve or purple.

The pods are 10 – 23 cm long, with 10 – 15 seeds per pod. The seeds are variable in size and shape, square to oblong and variously coloured, including white, brown, maroon, cream and green.

West Africa, where the highest genetic diversity and the most primitive forms of wild Vigna unguiculata occur, was probably the primary centre of domestication. Today, cowpea is cultivated throughout the tropics and sub-tropics between 35ºN and 30ºS Latitude. It is one of the most widely used legumes in the tropical world, the seed being used for human nutrition, especially in Africa, the leaves and flowers as vegetables, the whole plant as fresh cut-and-carry forage for animals, and for hay and silage. In some parts of Africa, particularly in northern Nigeria, they mix different varieties of cowpea for both human and animal food. In Australia, cowpea is grown as a green manure crop in coastal sugarcane areas, as a forage or dual-purpose grain and forage crop in coastal areas of Queensland, and as a grain crop from central Queensland to central NSW. Goodness knows how it reached Yule Street, Picnic Bay!

Cowpea has the potential to make excellent hay. When grown specifically for this purpose, its quality can equal lucerne hay. Even in smallholder systems, when used as a dual-purpose legume, residues can be used as animal feed or for soil enhancement. In West Africa cowpea hay is an important product for sale in local markets. Excellent hay, and also silage, can be made by harvesting a mixed crop of cowpea and forage sorghum or millet.

The strengths of cowpea are:

      • multi-purpose legume providing leaf, grain and forage;
      • improves soil fertility;
      • easy to establish;
      • very high nutritive value and palatability;
      • adaptable to a wide range of soils;
      • drought tolerant;
      • high yields in a short period of time, and
      • high seed production.

Several Lepidoptera use this as a food plant for their larvae, including:

      • the Cupid butterfly Euchrysops cnejus;
      • the moth Mocis trifasciata; and
      • the moth Eublemma dimidialis.

Photographs taken at Picnic Bay 2010
Page last updated 26th April 2019