Bushy shrub, often heavily branched, to c. 1.6 m tall. Branchlets either uniformly and minutely puberulent, or glabrous. Leaf bud sinus, rounded to subacute, usually conspicuous, but sometimes (on Mokohinau Islands) very small. Leaves obovate, oblanceolate or narrowly elliptic, subcoriaceous to very robust and coriaceous, (30–) 45–95(–125) mm long, (7–)10–25(–31) mm wide; upper surface dark to very dark green; underside of lamina glabrous; underside of midrib glabrous or hairy, hairs when present being < 0.2 mm long; margins pubescent to sparsely ciliate or nearly glabrous. Inflorescences 5.5–14.5 mm long. Outer surface of calyx lobes glabrous or hairy (always glabrous on plants from the Mokohinau Islands). Corolla lobes faint mauve to vivid purple-mauve when young, usually fading to white after anthesis, outer surface either glabrous (but with margins often ± ciliate near base) or hairy (always glabrous on plants from the Mokohinau Islands); corolla tube (2.5–)3–5.5 mm long. Ovaries usually sparsely hairy (especially along septal grooves), sometimes glabrous.

A subspecie pubescens et subspecie rehuarum foliis obovatis oblanceolatis vel anguste ellipticis, paginis infernis foliorum glabris et costis infernis glabris vel pilis brevioribus quam 0.2 mm vestitis differt.

2n = 40

2n = 40

2n = 40