Much-branched, bushy and widespreading, unarmed shrub, to c. 2.5 m tall; hairs mostly simple; stems 4-ribbed except towards base of plant. Petioles 5-10-(20) mm long, slender. Lamina 2.5-6-(10) × 0.8-2.5-(6) cm, usually lanceolate-ovate to elliptic, sometimes broader, entire, puberulent, especially on midrib below; base attenuate; apex obtuse. Cymes with < 5 fls; peduncles 0; pedicels very slender. Calyx 4-5 mm long, puberulent; lobes small, subulate. Corolla 1.5-2.5-(3) cm diam., violet or deep blue with yellow centre; lobes very small, hairy, acute. Anthers c. 3 mm long. Berry not seen.