Description from Flora of China
Gonotheca blumei Candolle; Hedyotis alata Koenig ex Wight & Arnott; Oldenlandia alata (Koenig ex Wight & Arnott) J. D. Hooker; O. pterita (Blume) Miquel; Thecagonum pteritum (Blume) Babu.
Herbs, annual or perennial, at least weakly erect, to 15(-30) cm tall; stems subterete to 4-angled, sometimes sulcate and/or winged, glabrous. Leaves subsessile to petiolate; petiole to 10 mm, glabrous; blade drying membranous, elliptic-oblong, lanceolate, or elliptic, 1-6 × 0.4-1.5 cm, glabrous, base cuneate to obtuse then often abruptly decurrent, apex acute or obtuse; secondary veins indistinct; stipules fused to petiole bases, triangular, 0.5-2.5 mm, glandular-puberulent to glabrescent, apically truncate or serrulate to prolonged and acute. Inflorescences terminal becoming displaced to pseudoaxillary in upper leaf axils by subsequent stem growth, 1-flowered or 2-8-flowered and cymose to fasciculate, glabrous, subsessile or pedunculate; peduncle to 1.5 cm; bracts reduced, triangular, to 0.3 mm; pedicels to 1.5 mm, winged. Flowers subsessile to shortly pedicellate. Calyx glabrous; hypanthium portion cupular to turbinate, 1-2 mm, with 4 wings to 0.6 mm wide; limb lobed for 1/2-2/3 its length; lobes ovate, ca. 1 mm, reticulately veined, dorsally winged to apex, sometimes ciliolate, acute to acuminate. Corolla white, outside glabrous; tube 1-1.5 mm, barbate in throat; lobes triangular, 1-1.5 mm. Anthers ca. 0.5 mm, included and positioned near base of corolla tube. Fruit capsular, turbinate to ellipsoid, 5-8 × 3-5 mm, glabrous, with 4 wings to 1 mm wide; seeds numerous, ca. 0.5 mm. Fl. Jul-Oct.
Thickets, slightly shaded wastelands. Guangdong, Guangxi [India, Malaysia, Philippines, Thailand, Vietnam].