Shrub 0·50–3 m. high, often sarmentose. Branchlets subquadrangular, stellate–tomentose when young, glabrescent. Leaves opposite or sometimes subopposite, shortly petiolate; stipules foliate, often only present on main branches; long; lamina narrowly ovate or narrowly elliptic, 3–6 times as long as wide, 4–20 x 1–7 cm., acuminate at the apex, cuneate at the base, serrate to subentire. Inflorescence terminal, sometimes also lateral, thyrsoid, long and rather narrow, 10–30 x 3–5 cm., rarely smaller, composed of mostly short–stalked, lax, many–flowered cymes. Flowers all shortly pedicellate or some sessile. Calyx narrowly campanulate, 2–3·5 x 1–1·5 mm., outside stellate–pubescent to glabrous, tube (1·5)2–5 times as long as the lobes; lobes subequal, usually narrowly triangular, 0·5–2 x 0·5–0·8 mm., acute or acuminate, entire. Corolla violet or lilac (white not seen in specimens in the field), orange–yellow within the throat, with erect lobes 3–5 times as long as the calyx, 7·5–14 mm. long, outside glabrous or stellate–pubescent and/or with minute glandular hairs; tube nearly cylindrical, 2–4 times as long as the calyx, 3–5·5 times as long as the lobes, 6–11·5 mm. long, 0·9–1·5 mm. wide below the throat and from there abruptly widened; lobes circular or slightly longer than wide, 1·3 x 1·3 mm., rounded, entire to crenate, spreading. Stamens included; filaments very short, mostly inserted in the middle of the corolla tube. Ovary oblong or nearly so, laterally compressed, glabrous, minutely pubescent, or sometimes with glandular hairs. Capsule narrowly ellipsoid or narrowly ovoid, (3)5–9 x 1·2–2 mm.