Cassia obtusifolia is an annual suffruticose herbaceous plant, which grows between 0.5 to 2 meters. And there are many branches on the upper part. Pinnately compound leaf is alternate; petiole is 2 to 5cm; leaflets are 3 pairs; blade is obovate or obovate-oblong, 2 to 6cm long, 1.5 to 3.5cm wide, and with rounded apex and cuneate base. Flowers are axillary in pair and the top ones are acervate; peduncle is very short; pedicel is about 1 to 2cm; sepals are 5 and obovate; corolla is yellow, obovate, 12 to 15mm long, and with 5 petals and base with claws. Pod is slender, four edged, 15 to 20cm long, 3 to 4mm wide, and with 2 to 4cm stalk. Seeds are numerous, nearly in prismatic shape or sometimes slightly flat, light brown, bright, and with linear oblique groove on each side. It usually blooms from June to August and fruits from August to October. Habitats include hills, roadside, barren mountain, hillside, and woodland.