Cleome angustifolia Forssk.

Erect glaucous herb 30-120 cm tall, simple to branched. Stems striate, pallid, glabrous to conspicuously aculeolate-glandular, sometimes with a fusiform swelling in the main stem. Leaves 3-9(-13)-foliolate, petiolate; petioles up to 6 cm long, glabrous; leaflets shortly petiolulate, glabrous, linear-filiform, 1-4(-5) cm long, 0.4-1(-2) mm broad, becoming progressively smaller towards the inflorescence and grading into the bracts. Inflorescence a lax terminal raceme; bracts 1-3-foliolate, sessile or sub-sessile; pedicels slender, 1-2.5 cm long, glabrous or sparingly glandular, elongating in fruit to 3 cm long. Sepals oblong-lanceolate to ovate, 5-10 mm long, 2-4 mm broad, glabrous to glandular, apex rounded or acuminate. Petals yellow with, usually, a violet basal area, narrowed to the base to a short claw up to 4 mm long; the two lateral the larger, broadly obovate to obovate-oblanceolate, 0.9-2.4 cm long, 0.5-1.2 cm broad, the two median oblanceolate, 0.6-2.1 cm long, 2-3 mm broad, rounded at the apex. Stamens 8-18; fertile stamens 2 or 4 with filaments up to 4 cm long, incurved; anthers about 4 mm long; staminodes 6-12(-16), 3-10 mm long, often clavate at the apex, with minute sterile anthers. Ovary linear, glabrous, 4 mm long; gynophore about 4 mm long; style 1 mm long; stigma capitate, minutely papillose. Capsule linear, 4-10 cm long, 3-4 mm broad, straight or slightly curved, spreading or deflexed; gynophore (0.5-)1-1.7 cm long, glabrous; style 5-10 mm long; valves glabrous or sparingly glandular, tapering to both ends, thin-textured, with about 9 anastomosing nerves on each side. Seeds brown, about 1.5 mm in diameter, surface reticulate-foveolate, subglabrous (when immature) or patently pubescent with bristle-like hairs of different lengths.