Gynodioecious shrub, up to c. 2 m tall. Branches erect; old stems grey; youngest branchlets olive-green, or red-brown; internodes (1-)4-13(-24) mm long; leaf decurrencies evident (usually weakly), or obscure; leaf-base scars evident; stem pubescence absent or bifarious, eglandular puberulent (when hairy). Leaf bud about as long as mature leaves with leaves of a pair separating when mature; sinus absent. Leaves decussate, free at base, spreading to recurved; lamina linear or linear-lanceolate or lanceolate or elliptic (especially var. oliveri or some North Island populations of var. stenophylla), subcoriaceous, folded or flat, (11-)23-53(-87) mm long, 2.5-6.5(-10) mm wide; apex acute; base cuneate; evident venation in fresh leaves consisting of midrib only or consisting of midrib and 2 secondary laterals arising from base; midrib slightly thickened beneath and depressed to grooved above; margin thickened, green, bevelled, mostly glabrous but occasionally pubescent, entire; adaxial surface green, dull, with few stomata or with moderately dense stomata, sparsely pitted (often only along margins) to conspicuously pitted with small depressions that each contain a twin-headed glandular hair, hairy along midrib; abaxial surface green, dull, with dense stomata (often many more than adaxial surface), conspicuously pitted with small depressions that each contain a twin-headed glandular hair. Inflorescences with (35-)55-130(-170) flowers, lateral, racemose and unbranched, (2.5-)4.5-6.5(-9.5) cm long, longer than subtending leaves, flowers generally opening in acropetal sequence; peduncle (0.5-)1-1.5(-2.1) cm long, eglandular pubescent; rachis (2-)4.5-6(-9) cm long, pubescent; bracts alternate, acute (mostly) or obtuse, eglandular ciliate or ciliate with both glandular and eglandular hairs, ovate or deltoid; pedicels ranging from much longer than bracts to equal to bracts, eglandular-pubescent or glabrous, erecto-patent to patent at anthesis, erecto-patent to patent or ascending at fruiting, (0.5-) 1-3(-5) mm long. Flowers protandrous, those on individual plants either hermaphrodite or female. Calyx 1.5-2.5 mm long, 4- lobed, equally divided; lobes all similar, ovate or oblong, obtuse to acute, eglandular ciliate (usually) or with mixed glandular and eglandular cilia (glandular hairs often with a single, rounded cell at the apex; twin-headed hairs, when present, usually sparse), margins membranous and sometimes tinged pink. Corolla white with lobes usually tinged mauve at anthesis, white after pollination; tube glabrous (usually) or hairy inside (especially var. hesperia), (1.8-)3-4.9 mm long, 1.3-2 mm wide, contracted at base and cylindric or expanded in lower half, longer than calyx; lobes glabrous, shorter than corolla tube; posterior lobe broad-ovate or circular, obtuse or slightly emarginate, suberect to recurved (mostly patent), with margin and apex turned upwards; lateral lobes usually broadly ovate to elliptic, obtuse, suberect to patent, with margin and apex turned upwards; anterior lobe elliptic to ovate, obtuse, patent, with margin and apex turned upwards, sometimes enfolding style or not enfolding style; corolla throat white. Stamen filaments white, diverging after anthesis, incurved at apex in bud, becoming straight after anthesis, 2.5-3.5 mm long; anthers obtuse (sometimes +/- emarginate) or apiculate, magenta, 1-1.5 mm long. Nectarial disc glabrous. Ovary ovoid, glabrous, 0.8-0.9 mm long, 2-locular; ovules 4-10 per locule, marginal in one layer on a flattened placenta; style 3-7 mm long, 0.12-0.2 mm thick, glabrous, pink; stigma subcapitate or capitate, yellow at anthesis, 0.12-0.25 mm wide. Capsules latiseptate, acute or obtuse, dark brown, (2-)2.5- 3.5 mm long, (0.8-)1.5-3 mm thick, glabrous, septicidal split extending to base, loculicidal split extending ¼-¾-way to base.