A scrambling shrub with hairy stems, sometimes rooting at the nodes. Leaves opposite, simple; petiole up to 0.5 cm long; blade elliptical, c. 7.5 cm × 3.5 cm, tapering at both ends, margin entire, with scattered simple hairs at both surfaces. Inflorescence cymose, 1–3-flowered, close together in the upper leaf axils, at apex of branches ending in a dense spike-like structure. Flowers bisexual, zygomorphic, up to 4 cm long; calyx 4-lobed, 2 outer lobes lanceolate, 13–17 mm long, 2 inner ones smaller, shortly bifid at apex; corolla bell-shaped, 2-labiate, white to very pale blue; stamens 2, anthers blue, staminodes 3; ovary superior, 2-celled, glabrous, style terete, glabrous, stigmas 2-lobed. Fruit a spindle-shaped, compressed capsule c. 1 cm long, 2-seeded. Seeds discoid, densely covered by brownish hygroscopic hairs.

PROTAbase: Barleria opaca

The leaves are also used to treat children for piles by squatting in a warm decoction. The whole plant is used in treating jaundice, rheumatism and paralysis, and the leaf sap is applied against catarrh.