Much, but loosely branched semi-prostrate rhizomatous herb forming extensive overground lax patches anchored by thick roots, 1-1.5 mm diam. evenly distributed along the underground portion of the stems; branches diverging at 45-60° from the axes, the stems tinged red, 2.0-2.5 mm wide, clothed in non-shaggy, long eglandular and glandtipped multicellular hairs, the stems distinctly upturned at the apices; internodes 0.3-1.3 (1.8) cm long, easily distinguished, especially on the more mature stems. Leaves mostly widely separated on the stems, subdistichous, suberect, somewhat delicate, light green, on long, slender, reddish, 3- nerved, pubescent petioles 0.8-2.0 (1.3) cm long, 2.5-7.5 (3.2) mm wide, persistent on the old stems; blades obovate-spathulate, 4-6 major veins salient on both surfaces, 1.5-5.0 (2.8) cm long, 0.8-2.2 (1.3) cm wide, apex obtuse, base attenuate, margin 10—17 (14)-crenulate, the divisions obtuse, asymmetrical, each with a small secondary hydathodal notch above the upper lh of the primary notch, upper leaf surface sparsely but evenly clothed in erect multicellular, eglandular pubescence sometimes interspersed with glandular hairs of equal length, pubescence on the lower leaf surface mostly glandular, limited to the raised veins, deciduous with age. Inflorescence slender, 3.7-11.2 (8.5) cm long in flower, 6.7-14.6 (11.3) cm long in fruit, moderately clad in gland-tipped pubescence, not shaggy, mostly < 1 mm long; bracts foliaceous, 2-3 borne at each of the 2-4 internodes, obovate-spathulate, < ½ the length of the inflorescence internodes, 0.5-1.5 (1.1) cm long, 0.5-1.2 (0.8) cm wide, reflexed, 3-5-nerved, distinctly 6-10-crenulate, adaxially clad in glandular and eglandular pubescence towards the tips, abaxially with glandular pubescence only along the veins. Flowers 1-2 per node, occasionally the lowermost node with only 1 flower; pedicels greatly exceeding the bracts in length, 1.3-2.5 (2.1) cm long in flower, 1.8-3.2 (2.3) cm long in fruit, glandular pubescent; calyx bilabiate, obtriangular somewhat inflated, light green, 0.5-1.2 (0.8) cm long, 0.8-1.0 (0.8) cm wide, base subacute, sparsely, but evenly clad in a mixture of non-shaggy glandular and eglandular pubescence externally, scattered pubescence on the inside; lobes of the calyx oblong, distinctly 3-nerved, 0.2-0.3 (0.3) cm wide, obtuse to retuse, the 2 anterior lobes cleft to the base, the 3 posterior lobes united for 2/3 to almost the entire length. Corolla to 1.3 cm wide, white except for the throat, purple both internally and externally, the pigmentation extending for some distance along the sutures of the 3 anterior corolla lobes, three rows of short, white retrorse hairs alternating with the purple prolongations superimposed over the pigmented area of the throat; tube erect, straight, short, 4.0-5.0 (4.5) mm long; corolla lobes oblong to oblong-spathulate, angular, emarginate, greatly exceeding the length of the tube, the 2 posterior lobes 9.0-10.0 (8.5) mm long, 5.0-6.0 (5.5) mm wide, somewhat spreading, the 3 anterior lobes 10.0-12.0 (11.0) mm long, 5.0-6.0 (5.8) mm wide, erect, longitudinal axis of the corolla much longer than the transverse axis; style short, 4.0-5.0 (4.2) mm long; filaments 4.0-4.5 (4.0) mm long; capsule ovate-oblong, overtopped by the expanded lobes of the persistent calyx at maturity; stigma white; seeds minute, light brown.
[Reproduced from Arroyo (1984, New Zealand J. Bot. 22: 447–463) with permission from The Royal Society of New Zealand.]