Shrubs to 3 m tall. Older stems grayish brown, subterete, lenticellate and tuberculate; young stems 4-angled, pilose. Petiole 1-2(-3.5) cm, pubescent; leaf blade elliptic to ovate, 4.5-8.5 × 1.5-4.5 cm, leathery, both surfaces glabrous, secondary veins 6 or 7 on each side of midvein and slender, base broadly cuneate, margin entire, apex acute. Cymes axillary, 1-3-flowered; peduncle 1.5-3 cm, pubescent; bracts narrowly lanceolate, 10-15 × ca. 1 mm, pubescent. Calyx 1-1.2 cm, abaxially gland-tipped hirsute, adaxially hirsute; lobes linear, apex acuminate. Corolla purple, 2-2.5 cm, both surfaces glabrous; tube basally cylindric and ca. 1.5 mm wide for 5-8 mm then gradually widened to ca. 8 mm at mouth; lobes oblong, ca. 4 × 3 mm, apex retuse. Staminal filament longer pair ca. 1 cm and shorter pair ca. 0.6 cm, pilose; anther thecae with 2 spurs at base. Ovary pubescent; style ca. 1. 4 cm, pubescent. Capsule linear-oblong, 1.3-1.4 cm, densely pubescent, usually 8-seeded. Seeds globose, ca. 3 × 3 mm. Fl. Aug.