Herb 0.2–1.2 m. tall, the stems quadrangular and woody at the base, pubescent or ± glabrous save at nodes. Leaves 3.5–7 x 1–2.3 cm., lanceolate, narrowly tapering acute at the apex, ± rounded at the base, ± pubescent or glabrous save for midrib beneath; petiole up to 3 mm. long; stipule sheath ± 2 mm. long with 2 short fimbriae 0.5–2 mm. long. Flowers in condensed terminal inflorescences on most upper branches, 2–4 cm. wide, closely surrounded by leafy bracts; pedicels up to 2 mm. long in fruit; occasionally an isolated axillary flower at lower node with pedicels to 5 mm., perhaps a reduced axillary branch. Calyx tube subglobose, 1.5–2 mm. wide, glabrous to sparsely pubescent; lobes 2–5.5 x 0.8–1.5 mm., lanceolate, acute, ciliate. Corolla pale blue, lilac or purplish pink; tube 1–1.7 cm. long, slightly widened at the apex for 4 mm., sparsely pilose-pubescent or ± glabrous, glabrous inside but with a ring of hairs at throat rim; lobes 2.5–4.5 x 1.5–2 mm., elliptic. Anthers included but stigmatic branches 1–2 mm. long, just included or shortly exserted. Fruit 5.5–7 x 4.5–6 mm. including the hemispherical beak, ovoid-globose; calyx-lobes ± persistent.