Canscora melastomacea Handel-Mazzetti.

Annuals, 20-40 cm tall, glabrous. Stems erect, much branched, obscurely 4angled. Leaves sessile, ovate-lanceolate to ovate, 1-5 × 0.5-2.5 cm, base cuneate to rounded, apex acute; veins 3-5, slender. Cymes pseudodichotomous. Flowers 4merous. Calyx tubular; tube 0.9-1.1 cm, membranous; lobes narrowly triangular, 3-4 mm, apex acute, veins 3 and prominent. Corolla white to purple, tubular, 1.4-1.8 cm; lobes elliptic to oblong-spatulate, 4.5-5 mm, margin entire, apex obtuse. Fertile stamens 1; filaments filiform, 2-2.5 mm; anthers ellipsoid, 1-1.2 mm. Sterile stamens 3; filaments 0.4-0.5 mm; anthers small. Style filiform, 8.5-10 mm; stigma lobes oblong. Capsules ellipsoid, 7-8 mm. Seeds 0.5-0.6 mm. Fl. and fr. Sep-Oct.

Weed in cultivated land, valleys, forests; 200-1400 m. Guangdong, Guangxi, S and SW Yunnan [Cambodia, India (Assam), Laos, Malaysia, Thailand, Vietnam].