Its leaves are leathery, dark to bright green in colour and up to 15–30 cm (6–12 in) long and its oval-shaped orange-coloured fruit is 30–40 mm (1.2–1.6 in) in length.

On the Chatham Islands, depictions of Moriori ancestors were carved on to karaka trees (known as rākau momori) and are considered internationally significant and unique to their culture.

Corynocarpus laevigatus (karaka) is a medium-sized evergreen leafy canopy tree with erect spreading branches endemic to New Zealand.

Younger trees have light brown bark that frequently has short, horizontal bands that resemble sewing stitches.

Karaka's dense shade and prolific seeding exclude local species and change the host community's composition and ecological processes in areas where it has been allowed to proliferate.

[6] From August to November, karaka produces large, stout, erect panicles of tiny greenish-yellow flowers, each less than 0.5 cm (0.2 in) in diameter.

[3][2] The fruit karaka produces is oval-shaped and 30–40 mm (1.2–1.6 in) in length; with pale yellow–orange coloured flesh and a poisonous seed which is smooth and elliptic.

[7][8] Karaka's wood anatomy prevents them from being dated using the conventional technique of counting annual growth rings in the trunk.

Sir Joseph Banks and Daniel Solander, who were the botanists on the first voyage of James Cook, also brought specimens of C. laevigatus to England, where they described and figured it under the name Merretia lucida, though their work was never published.

Fossilised Corynocarpus kernels from the early Miocene era were found at Landslip Hill in the Southland Region, this discovery indicates that the genus has a long history in New Zealand.

[17][18] In the far north of New Zealand, where kauri (Agathis australis) forests are its natural vegetation type, the density of karaka is low (2.5 stems per hectare).

A 2006 study by the New Zealand Journal of Botany indicated an average canopy coverage across plots in karaka stands was 41%, with a maximum cover of 75%.

[6] The species was naturally not present in the Otago and Southland Regions of New Zealand prior to human settlement, all the karaka individuals south of Banks Peninsula are likely to be recent horticultural introductions.

[6] Other smaller New Zealand birds such as the North Island robin (Petroica longipes), silvereye (Zosterops lateralis) and whiteheads (Mohoua albicilla) are known to search around karaka trees for insects.

[1] It was one of the most grown food crops by pre-European Māori (alongside kūmara and aruhe); they ate the drupe and seed after a long detoxification process.

[33][34][35] Initial symptoms of poisoning include diarrhoea, nausea and restlessness which develop to more severe gastrointestinal and neurological problems.

[41][42] While pre-European Māori primarily valued karaka for nutrition rather than medicine, they did use leaf undersides to draw out infections and fresh upper surfaces to heal injured skin.

[46] A 2000 Department of Conservation report documented 147 karaka trees with dendroglyphs on the Chatham Islands, though not all carvings were confirmed as authentically Moriori.