Cajanus

Cajanus is a small genus of flowering plants in the legume family, Fabaceae. It includes several species, the most important being Cajanus cajan, the pigeon pea or red gram. Native to the Indian subcontinent, Cajanus species are now grown in tropical and subtropical regions worldwide, particularly in semi-arid zones of Africa, Asia, and the Americas.

Cajanus cajan is a woody perennial shrub or short-lived vine that is often cultivated as an annual. It typically reaches 1–2 meters in height and bears pinnate leaves and lavender to pink flowers. The fruit is a hairy pod containing several seeds. The species is valued for drought tolerance and for its ability to fix atmospheric nitrogen via rhizobia, improving soil fertility. It is used as a pulse crop for human consumption and as forage for livestock, and it can serve as a green manure or cover crop.

In human use, pigeon pea seeds are cooked as dried pulses, ground into flour, or processed into dals and curries in parts of India and East Africa. Leaves and young pods are edible in some cuisines. Breeding programs aim to improve yield, disease resistance, and adaptation to marginal environments, with international research initiatives contributing to genetic improvement and seed dissemination. See also: pigeon pea.