Spring Sida

Nile region, Oases and Mediterranean region.

Tropical and Subtropical Regions.

Erect, annual or perennial, stellate pubescent, 30 cm to 1 m tall undershrub. Leaves with filiform, 2-5 mm long stipules; petiole 2-20 mm long; 1-3 spiny tubercles present on stem at the base of petiole; blade 0.5-4 cm long, 0.3-2.5 cm broad, lanceolate to ovate, oblong or somewhat orbicular, rounded at base, acute or obtuse at apex, serrate, usually cinereous on both surfaces. Flowers axillary, solitary or 2-5 in fascicles in terminal branches; pedicel 2-5 mm, in fruit up to c. 2 cm long, jointed near the middle or top. Calyx 4-5 mm long, c. 5 mm across, slightly accrescent, fused somewhat above the middle; lobes triangular; acute to acuminate, 1-2 mm long. Corolla white, exceeding the calyx. Fruit depressed globose, pubescent above; mericarps 5, membranous, 2-3 mm long, trigonous, dehiscent at apex but seed released from the disintegrated base, radially striately nerved, apically with 2, 0.5-0.8 mm long, divergent awns. Seeds c. 1.5 mm long, glabrous, brown to black.

Sida spinosa is a weedy plant native to certain tropical areas such as the Neotropics and parts of tropical Asia, that has become a widespread alien species in many temperate zones. It is the target of benzoate herbicides in many agricultural areas.

Also known by the common name of Prickly fanpetals, this adventive annual is approximately two to five centimeters in height. Stems are covered with fine white hairs. Alternate ovate or ovate-oblong leaves attain lengths of up to five cm; the leaves are maginally crenate, and sparsely covered with very fine hairs. Leaves exhibit petioles up to 2.5 cm in length.