Common Name: Coffee senna. Tamil Name: Kattuttakarai, Narattantakarai.
Coffee senna is a pan tropical plant of American origin naturalized in India. It is an annual can grow to about 2 feet and often seen on road-sides in Coimbatore city. The leaves are alternately arranged and bipinnate and paripinnate. The leaflets number around 5-7 pairs and are arranged in opposite manner. The leaf stalk measure around 4.5 cm; notable leaf gland is present about 2 mm away from the base of the leaf stalk. The leaves measure around 3.1 cm in length and 2.1 cm in breadth and are oblong-lanceolate in shape. The base is attenuate and tip acute. The inflorescence is in the form of an axillary corymb. The flower is five segmented and yellow in color. The pod measure 10.5 cm in length; upward curved and brown in color. They hold about 20-25 seeds. The seeds are about 3 mm in size and sub-orbicular in shape and brown in color. The plant is poisonous to cattle. The seed is roasted to make a brew-a coffee substitute. The powder is now sold in markets. The plant is known to have several medicinal applications. There are some reports indicating that it should not be consumed by children. Senna occidentalis is known to inhibit the growth of Parthenium hysterophorus which is an obnoxious weed. This plant is the larval host plant for Lemon emigrant and Mottled emigrant butterflies.