Description from Flora of China
Annuals, erect, to 40 cm tall. Stems usually branched, subquadrangular, striate, puberulent, nodes inflated. Petiole to 2.4 cm, winged; leaf blade oblong to ovate-oblong, to 12 X 5.3 cm, abaxially glabrous but veins puberulent, adaxially puberulent, base broadly cuneate and often asymmetrical, margin rounded serrate, apex acute. Racemes to 15 cm, glandular hairy; bracts linear, ca. 2 mm. Pedicel to 2 cm. Calyx lobed to base; lobes irregular, linear, 3-veined, upper lobe almost 2 X as long as other lobes and to 1.5 cm after flowering. Corolla white, to 1.2 cm; lower lip 3-lobed, middle lobe broadly ovate and larger than narrowly ovate lateral lobes; upper lip triangular-ovate, margin entire. Stamens didynamous; anterior filaments basally with a reniform appendage. Style included; stigma 2-lamellate. Capsule ovoid-ellipsoid.
Because the name was not validly published at first (Acta Phytotax. Sin. 8: 67-68. 1959), it was validated by Xiang Chunlei and Peng Hua (Nordic J. Bot. 26: 41. 2008).
* Dense forests. Guangdong, Guangxi, Hainan.