Erect or ascending subherbaceous shrub, 20–60 cm. to 1 m. tall, much branched; branches opposite to subopposite, erect to spreading, minutely pubescent below, viscid glandular-pubescent above, leafy particularly below inflorescence. Leaves 5–11(38) x 2.5–16(20) mm., broadly ovate, ovate-elliptic to subcircular, apex obtuse, cuneate at base, coarsely dentate with obtuse or rounded teeth, subglandular-pubescent or shortly pubescent on both surfaces, petiolate. Petiole short or up to half length of leaf. Inflorescence racemose or cymose with simple or compound racemes in terminal leafy panicles. Pedicels 2–4(10) mm. long, slender, finely pubescent to glandular-pubescent. Bracts opposite, lanceolate, subulate, or lower similar to but smaller than leaves, acute, entire or sparingly dentate. Flowers blue, pinkish-mauve to purple or white, with yellow or orange centre. Calyx 4–8 mm. long, deeply 5-lobed, softly hispid to glandular-pubescent; lobes linear-lanceolate to subulate, acute. Corolla tube 5–9 mm. long, narrowly infundibuliform, minutely finely glandular-pubescent without; limb 4.5–5.5 mm. in diam.; lobes c. 2 mm. in diam., glandular-pubescent beneath, broadly oblong-ovate to subcircular. Capsule 3–4 mm. long, ovoid, glabrous.