Description from Flora of China
Herbs to 30 cm tall, perennial. Stems terete, villous. Leaves cauline, crowded at apex of branches; petiole 1-3 cm, densely villous; leaf blade oblong to oblong-lanceolate, 3-10 × 1.3-3 cm, subleathery, abaxially adpressed villous, adaxially glabrous except midvein slightly villous, secondary veins 6-10 on each side of midvein, base cuneate to broadly cuneate, margins entire or irregularly undulate, apex rounded. Racemes terminal or axillary, to 16 cm; rachis pubescent; bracts linear-spatulate to linear, ca. 2.5 mm, 1-veined; bracteoles similar to bracts. Pedicel ca. 3 mm. Calyx 6-7 mm, subglabrous; lobes linear, unequal, 3-veined, apex acuminate. Corolla purple, ca. 8 mm; lobes ovate-oblong, 1.2-1.4 × ca. 1 mm, apex rounded. Stamens with longer pair ca. 5 mm and shorter pair ca. 3 mm; filaments glabrous; anther thecae of longer stamens unequal and of shorter stamens equal; staminode ca. 0.7 mm. Ovary ovoid, ca. 1 mm, glabrous; style ca. 6 mm. Capsule ovoid-oblong, ca. 5 mm, glabrous. Fl. Feb-May, fr. Jul-Aug.
● Streamsides; 600-900 m. Hainan.