Description from Flora of China
Torenia polygonoides Bentham, Scroph. Ind. 39. 1835.
Herbs, subglabrous. Branches slender. Petiole 0.5-0.8 mm; leaf blade ovate-elliptic to ovate-rhomboid, 1-2 cm, papery, glabrous, margin crenate-serrate on distal 2/3. Inflorescences 1-4-flowered; peduncle 0.5-1.5 cm; involucral bracts 2, acerose, ca. 1 mm. Pedicel 2-6 mm; bracteole subulate, 1-2 mm. Calyx oblong to suborbicular, to 9 mm in fruit, base short auriculate, wings to 4 mm wide, apex with 3 small sharp teeth. Corolla white or purple-blue, slightly longer than calyx; lower lip 3-lobed; upper lip entire; lobe apices obtuse. Capsule oblong-ovoid, ca. 8 mm. Fl. and fr. Jul-Aug.
Trailsides, shady and wet places of mountain valleys. Guangdong, Guangxi [Indonesia, Malaysia, Myanmar, Philippines; Oceania].