Botanical Description:

Red gram [Cajanus cajan (L.) Millsp.] belongs to family Leguminosae. Numerous nodules are present on roots, these nodules contain Rhizobium bacteria, which fixes atmospheric nitrogen. The flowers are self-pollinated but cross-fertilization may also occur to some extent. The fruit of the Red gram is a pod. Seeds are round or lens shaped.

Numerous species of Cajanus are known, differing in height, habit, time of maturity, colour, size and shape of pods and seeds. All these cultivated types belong to two categories:

1. Cajanus cajan var. bicolor: This group includes late maturing varieties, having tall bushy plants and bear flowers at the end of the branches. The pods are relatively longer and contain 4-5 seeds.
   
2. Cajanus cajan var. flavus: This group includes early maturing varieties, having smaller plants and flowers at several points along the branches. The pods are also shorter which bear 2-3 seeds.