Ruellia patula Jacq.

Perennial or shrubby herb or subshrub; stems to 0.5 (1) m long, erect to decumbent, rarely creeping and rooting at nodes, when young sericeous to sericeous-puberulous or sparsely so with downwardly directed hairs, rarely puberulous, often with longer broad glossy curly hairs to 2 mm long, occasionally with stalked capitate glands. Leaves puberulous or sparsely so, densest along veins; petiole 2-20 (32) mm long; lamina ovate to elliptic, largest 1.5-6 (8) x 0.8-3 (3.8) cm; apex acute to rounded; base attenuate to truncate. Flowers solitary or in 3-flowered axillary cymes, rarely with two 3-flowered cymes per axil; pedicels (peduncles in cymes) 0.5-6 (8) mm long, glabrous to puberulous; bracteoles (bracts in cymes) 6-20 x 3-15 mm, ovate to elliptic or narrowly so. Calyx 4-8 mm long, divided to 1-2 mm from base, uniformly puberulous or with ciliate lobes and midribs; lobes narrowly triangular. Corolla falling early in morning, white to mauve; tube 12-33(50) mm long of which basal cylindric part 2-21 (32) mm and throat 9-16(20) mm long; lobes 5-13 x 6-15 mm, ovate-elliptic or broadly so with entire to crenate-dentate margin. Stamens included in throat, didynamous, anthers not or slightly overlapping; filaments fused for 1-3 mm at base, free parts 2-8 and 4-10 mm long; anthers 2-3 mm long. Ovary glabrous; ventral stigma lobe 1-1.5 x c.0.5 mm. Capsule clavate, glabrous, 15-20 mm long, 4-18-seeded. Seeds broadly ellipsoid to circular, dark brown, 3-4.5 x 2.5-4.5 mm.

It is a tropical plant.