Tree to 25 m, 1.2 m dbh. Branchlets pale grey and glabrous. Leaves evergreen and leathery, simple, 2–10 × 1–4 cm, elliptic to ovate, upper surface dark green and glossy, lower surface glabrous, with major veins slightly raised, six to nine secondary veins on each side of the midvein, margins coarsely serrate, apex obtuse; petiole to 2 cm long, pubescent on upper surface; stipules ligulate, caducous. Juvenile leaves simple, three-lobed or trifoliolate; leaves of reversion shoots up to five-foliolate. Inflorescence terminal, composed of two racemes; vegetative growth may continue from between the racemes. Flowers hermaphrodite, up to 1.2 cm long, pedicellate, petals white or pale pink, styles 0.3–0.4 cm long and persistent. Fruit a capsule to 0.5 cm long. Flowering December to January, fruiting January to April (New Zealand). Allan 1961, Wardle 1966, Hopkins 1998a, 1998b. Distribution NEW ZEALAND: North Is., South Is., Stewart Is. Habitat Weinmannia racemosa is one of the most abundant of all New Zealand trees and occurs in a variety of habitats, between 0 and 1100 m asl. USDA Hardiness Zone 9. Conservation status Not evaluated. Illustration Salmon 1996, Hopkins 1998b; NT893. Cross-references B751, K457. Taxonomic note Two species of Weinmannia occur in New Zealand and they can be difficult to distinguish. Weinmannia sylvicola Sol. ex A. Cunn. differs from W. racemosa in that the branchlets and pedicels are typically pubescent, the adult leaves are mostly trifoliolate and the juvenile leaves have up to 10 leaflets. The former occurs only on North Is. (Allan 1961, Wardle 1966). It is cultivated in Tasmania (from where seeds have been distributed: K. Gillanders, pers. comm. 2008) and in California, and elsewhere under glass.
Despite its abundance in New Zealand, Weinmannia racemosa is a rare plant in most of our area, probably because it is not hardy in any but the mildest of conditions. In principle it would seem very well suited to western coasts of Europe and North America, especially in moist sheltered places, but unlike its Chilean cousin W. trichosperma, no large plants of it have been traced. It has not become established at either Logan or Tregrehan, where it might have been expected to thrive, and although present in various other collections this is only as recent plantings. It is in commerce in the United Kingdom, sometimes under its Maori name Kamahi, applied in the form of a cultivar name. It is, however, established in California: for example, at the San Francisco Botanical Garden. With its upright, conspicuous inflorescences of pinkish white flowers held above the foliage it is distinctive and attractive, and worth trying where it has a sporting chance.