Sida spinosa L., Sp. Pl. 683. 1753; Masters in Fl. Brit. India 1: 323. 1874.

Annual or perennial, erect or diffuse herbs or undershrubs, ca 60 cm high; stems with 1 - 2 spiny emergences at the base of petioles; stems, petioles and pedicels cinereous with minute stellate hairs. Leaves 6 - 30 x 4 - 25 mm, ovate to oblong, rarely orbicular, acute rounded or truncate at base and apex, serrate, 3 - 5-nerved at base, stellate-pubescent on both surfaces, sometimes glabrescent above; petioles 2 - 25 mm long; stipules 1 - 2.5 mm long, linear, hairy. Flowers axillary, solitary or 2 - 5 in clusters; pedicels 2 - 8 mm long, accrescent up to 8 mm, jointed above the middle. Calyx 3 - 5 mm across, campanulate, lobes free above the middle, 1 - 2 x 1.5 - 2 mm, triangular adnate to acuminate with a prominent midvein, cinereous with minute stellate and scattered simple hairs outside, glabrous inside except for apical margins. Corolla yellow or yellowish white. Schizocarps enclosed within calyx; mericarps 5, 2 - 3 mm long, trigonous with 2 divergent, 1 - 1.5 mm long awns, apex of mericarps and awns stellate-hairy, dorsal portion with prominent reticulation. Seeds 1 - 1.5 mm long, slightly trigonous, glabrous, brownish-black.

Fl. & Fr. March - Dec.

Distrib. India: In waste places up to ca 900 m. Throughout.

Pantropical.