Cowpea is its scientific name, while jar bean is generally a dialect name. Different regions have different names for cowpea, as well as beans, long beans, kidney beans and carob.

Cowpea is an annual plant in Leguminosae. There are three kinds of stems: dwarf, semi-tendril and tendril. The cultivation in south China is mainly vine, followed by dwarf. An annual twining herb of Papilionaceae, with 3 leaflets, the terminal leaflet rhomboid-ovate, 5~ 13 cm long and 4~7 cm wide.

The top of cowpea is acute, the base is nearly round or wide wedge-shaped, both sides are hairless, and the lateral leaflets are obliquely ovate. Stipules ovoid, about 1 cm long, with a short distance below the place where they are planted. Calyx campanulate, glabrous; Corolla lavender, about 2 cm long, with yellowish whiskers in the upper part of the style. Pods are linear and drooping, up to 40 cm long.

Growth habit

Cowpea requires high temperature and has strong heat resistance, and its growth temperature is 20~25℃. It can still bear pods normally at high temperature above 35℃ in summer, but it is not resistant to frost, and its growth is inhibited at low temperature below 10℃ for a long time. Cowpea belongs to short-day crops, but as a vegetable, cowpea mostly belongs to light, and the requirements for sunshine are not strict, such as red-billed swallow, Zhijian 28-2 and other varieties, which can be cultivated in spring, summer and autumn in southern China.