Prostrate to erect woody subshrub, usually forming open straggling patches about 20 cm (but up to 1 m) across and up to 50 cm tall. Stems woody, sparsely branched, densely bifariously (rarely uniformly) pubescent (sometimes glabrous), brown, sometimes reddish or almost black, paler with age, rooting at lower nodes when in contact with the ground, leaf scars prominent. Leaves decussate, flattened into one plane on prostrate stems, lamina linear, lanceolate, ovate, obovate, rhomboid or obtrullate, serrate, glabrous except sometimes for midrib above, usually dark green above, sometimes light green or glaucescent, dull or shining, paler green or almost white beneath, (5)-7-40-(90) × 3)-5-20-(30) mm, apex acute, rarely subacute or obtuse, midrib depressed above, prominent below, leaf base sometimes truncate or subcordate but usually cuneately narrowed into short adaxially pubescent petiole (1)—2—5 × 1 mm, or leaf subsessile. Racemes axillary, erect, 6-30-(50)-flowered, peduncles 3-10 cm long, usually stout, glabrous or rarely pubescent; lower bracts often subfoliaceous, upper bracts linear to narrow-ovate, glabrous to hairy, sometimes glandular, 3—5—(10) mm long; pedicels slender, pubescent to glandular, sometimes glabrous, 6-10-(20) mm long. Calyx 4-lobed, tube very short, lobes ovate to obovate, acute, often acuminate by incurved margins, ciliolate, sometimes glandular, 2-5 mm long. Corolla white, rarely pale lavender, 8-12 mm diameter, tube yellow and pubescent within, 0.5-1 mm long, surrounded by magenta or purple (rarely pale mauve) ring at throat giving off radiating magenta or purple nectar guides to lobes, especially the posterior lobe (see Garnock- Jones 1976, fig. 1B), lobes four, unequal, 4-7 × 2-6 mm, ovate-oblong to suborbicular, obtuse, posterior lobe often emarginate to almost divided, lateral lobes longitudinally folded. Stamens spreading, 3-6 mm long, anthers held in folds of lateral corolla lobes. Ovary c. 1 mm long, style 3- 7 mm long, glabrous. Capsule exceeding the calyx (sometimes only slightly), narrowly to broadly obcordate, only slightly flattened, angustiseptate, glabrous, 2.5-4 × 2.5-4 mm, dehiscing by a septicidal split to the base and a loculicidal split c. half way to the base, style usually persistent for a while. Seeds many, oval, flattened, light brown, c. 1 × 0.6 mm.

Stems brown, prostrate, decumbent or erect, bifariously hairy, rarely more than 30 cm tall. Leaves narrow-lanceolate to ovate to rhomboid, widest between petiole and middle, usually shallowly toothed, acute at apex (sometimes acuminate in ovate-leaved forms), green beneath, (0.5)-1.5-3-(4) × 0.5-1-(2) cm. Inflorescences few- to manyflowered, (5)—10-15—(20) cm long; peduncle slender to stout, usually glabrous, (2)—5—(10) cm, rachis and pedicels uniformly eglandular-hairy, sometimes glandular-hairy as well. Bracts and calyx ciliolate, sometimes glandular or glabrous. Corolla with magenta ring at throat, anterior lobe <2 mm wide. Capsule light to dark brown, (2.5)-3-(3.5) × 3-4 mm.

Stems brown (sometimes drying black), erect, bifariously hairy, 10-30-(45) cm tall. Leaves linear to narrow-lanceolate, widest between petiole and middle, usually shallowly toothed, acuminate at apex, green beneath, (3)-4-7-(10) × 0.3-1-(1.2) cm. Inflorescences many-flowered, (5)—10—15—(20) cm long; peduncle stout, glabrous or with eglandular hairs, 3-7 cm long, rachis and pedicels uniformly eglandular-hairy, very rarely glandular as well. Bracts and calyx ciliolate or rarely glabrous. Corolla with magenta ring at throat, anterior lobe >2 mm wide. Capsule light to dark brown, (2.5)-3-3.5 × 2.5-3 mm.

Stems purplish black when young, prostrate to ascending, rooting at nodes, glabrous or with very sparse bifarious hairs. Leaves obovate to oblanceolate, widest about or above the middle, shallowly toothed, obtuse to broadly subacute at apex, green beneath, (0.5)-0.8-2 × (0.3)-0.6-1 cm. Inflorescences many-flowered, (7)-10-15—(20) cm long; peduncle stout, (5)-6-10 cm, peduncle, rachis and pedicels glabrous or sometimes uniformly glandular- hairy. Bracts and calyx glabrous or sparsely glandular-ciliate. Corolla with pale mauve ring at throat, anterior lobe <2 mm wide. Capsule black or dark purplish brown, 2.5-3.5 × 2.5-3.5 mm.

Subspecies ab his characteribus distinguenda: Culmi prostrati vel adscendentes, juvenes atro-purpurei, glabri vel parce villosi. Folia obovata vel oblanceolata, apice obtusa vel late subacuta. Pedunculus, rachis pedicellique glabri vel glanduloso-villosi. Corollae faux pallidemalvaceo annulo circumdata, lobus anticus quam 2 mm angustior.