Tree up to 10 m. tall or more; glab. or nearly so, except for stellate pubescence on young parts and infl. Branchlets slender, grooved, with pale bark. Juvenile plant similar in lf-form to adult or sts with branchlets very slender, divaricate, ± entangled; petioles very slender, up to 10 mm. long; lamina (5)-10-30 mm. long, broad-ovate to deltoid to suborbicular in outline, serrate, ± deeply lobed (teeth sts crenate). Lvs on reversion shoots similar. Adult plant with lvs on petioles up to c. 2 cm. long; lamina subcoriac. to submembr., (5)-7-14 × (3)-4-6 cm., broad-ovate to ovate-lanceolate to elliptic, acuminate (occ. lvs acute to obtuse or rounded), rounded to truncate to subcordate at base; deeply, coarsely, ± doubly, serrate-dentate. Fls c. 25 mm. diam., both solitary and in (2)-5-10-fld cymose clusters on same plant; pedicels c. 10 mm. long; calyx campanulate, ± 5 mm. long, teeth triangular; petals ± 10 mm. long, white; stigmas capitate. Mature carpels 5-(6), compressed, 5-7 × 5-7 mm. including broad wings.

Cunningham (Ann. nat. Hist. 3, 1839, 319) describes the lvs as "ovate valde acuminata, grosse duplicato-serrata, membranacea, penninervia, venosa". This agrees well enough with Hooker's (Handbk N.Z. Fl. 1864, 31): "Leaves ovate, with large sharp teeth". Forms closely resembling the type appear to be more common in the northern part of the range of the sp.

2n = 42

n = 21