Description from Flora of China
Herbs annual, glabrous, 7--50 cm tall. Stems erect or arcuate at base, quadrangular, usually much branched. Leaves alternate, rarely subopposite on lower part of stems; petiole 5--10 mm, narrowly winged; leaf blade ovate to rhomboid-ovate, 0.5--3.5 X 0.5--1.5 cm, sparsely dark purple or brown glandular punctate and striate, base attenuate, apex acuminate to acute. Pedicel 1--2 mm. Flowers solitary, in axils of upper leaves. Calyx lobes lanceolate, 3--4 mm, dark red glandular striate outside except on apex, margin membranous, apex ± recurved. Corolla white or pink; tube ca. 1 mm; lobes oblong-spatulate, 2--3 mm, reddish brown glandular striate, apex obtuse. Stamens included; filaments adnate to base of corolla lobes, free parts ca. 1 mm; anthers ovate, dorsifixed, ca. 0.5 mm. Ovary glabrous; style ca. 1.5 mm. Capsule globose, ca. 4 mm in diam. Fl. Jun.
At margins of cultivated fields, grassy mountain slopes; 200--3200 m. SE Xizang, C and N Yunnan [Bhutan, India, Kashmir, N Myanmar, Nepal, Pakistan].