Derris trifoliata: Common Derris

Family: Fabaceae
Common name: Common derris, Sweet derris, Ponnamvalli, Karanjvel

Common derris is a leguminous perennial that can grow to a height of up to 15 meters spreading over large areas by climbing on surrounding vegetation. They can also stay short, about 3-5 meters if they do not find something sufficiently tall to climb on. These plants are native to Southeast Asia, including India, Sri Lanka, and Bangladesh.

The plant has a slender stem and leaves that consist of three leaflets, giving the plant its name ‘trifoliata’. The leaflets are dark green, about 15-20 cm. Derris plants are commonly seen in the wild in tropical countries, near canals, lakes, rivers, mangroves, and other water bodies.

They can be grown as ornamental garden plants since they can attract pollinating insects, birds, and ants with their light pink or white flowers. Common Derris flowers are about 1 cm long, borne on tall racemes that are 8-15 cm long. Like most leguminous plants, these plants produce seed pods that are about 3-4 cm long bearing 2-3 seeds.

Common Derris flowers have a dark pink calyx, making them very similar to the flowers of Millettia pinnata or Indian beech tree, especially in the bud phase.

The plant prefers warm and humid climates and can tolerate partial shade. They require well-drained soil and moderate watering only during the summer months.

To keep the plant healthy and attractive, prune it regularly to remove any dead or damaged parts. Fertilize the plant with a balanced fertilizer during the growing season to encourage growth and blooming.

Common Derris plants might attract pests such as aphids and spider mites, which can be controlled using insecticidal soap or neem oil. Like other leguminous plants, Common Derris roots can fix atmospheric nitrogen turning them into nitrates and nitrites, which can then be absorbed easily by other plants.

These plants contain a poisonous chemical called rotenone which is commonly used as a fish poison. It is also mildly toxic for insects, small animals, and also human beings.

Derris plants have been used for centuries in traditional medicine to treat a variety of ailments like sores, skin diseases, fever, stomach ailments, malaria, and arthritis. The roots of the plant contain a high concentration of rotenoids, which have insecticidal properties and are used in agriculture to control pests.

Thick fibers obtained from the stem are used to make fish nets and ropes, and the leaves are used to make insecticides.

Propagation is through seeds and stem cuttings.