Senna uniflora - Oneleaf Senna

Oneleaf Senna is a woody, annual, erect herb, 15-20 cm high, young branches are appressedly hairy, old hairless. Branches and branchlets are 4-5 angled. Leaf-rachis is 6-12cm long (including the stalk), leaflets 3-5 pairs (usually 4 pairs), ovate-lanceshaped to inverted-lanceshaped with a sharp point at the tip, 2-5 × 1-2.5 cm. Leaflets are yellow-hairy on lower side, white velvety to hairless on upper side, nerves 4-5 pairs, prominent on lower side. Stipule are 6-10 mm long, linear, bristle-like persistent. Flowers are borne in 3-4 flowered racemes in leaf axils. Flowers are yellow. The flowers cluster is carried on a 1 cm long stalk. Flower stalks are smaller, 2-4 mm long, rufous. Bracts are linear, hairy. Sepals are 4-6 mm long oblong-suborbicular, obtuse, ciliate, outer rufous hairy, inner ones velvety. Petals yellow, obovate, 6-10 mm long prominently veined. Fertile stamen are 7, three large anthers narrowed like neck of bottle, rest anthers rounded at the top. Ovary is densely silk-hairy. Pods are 3-5cm long, linear, obscurely 4 angled (2-angles sharply margined), 5-1 seeded, appressedly hairy, obscurely pointed at tip. Seeds are dark brown 0.4-0.7cm long. Oneleaf Senna is native to Central and South America, fast naturalizing in India - has been reported from Karnataka, Madhya Pradesh, Maharashtra and Rajasthan. Flowering: August-December.