Scientific species name: Corynocarpus laevigatus
Corynocarpus, from the Greek, meaning club seed.(2) laevigatus smooth, referring to the leaves (6)
Family: Corynocarpaceae; a small family of one genus with five species of trees confined to the New Guinea, New Hebrides, New Caledonia, Queensland and New Zealand. The genus Corynocarpus has the same distribution as the family. Only one species, karaka, occurs in New Zealand.(1)
Maori name (s): Karaka, kopi (5)
Common name(s): Karaka
Description: The karaka has large dark green, glossy leaves that remind us that it is a family from the tropics. In Auckland the tree produces masses of off-white, slightly scented, flowers in early spring (Aug- Nov) and usually carries a heavy crop of large bright orange fruit in mid to late summer (Jan-Feb).
The flowers are quite small, up to half a centimetre each, and are most likely pollinated by insects. The light colour and the scent could even mean that karaka flowers might be pollinated by moths at night. 
The fleshy fruit is very large by New Zealand standards, 2.5 to 4 cm long and 2 to 3 cm in diameter, and ripens from green through to orange. The only bird capable of eating this fruit whole is the native pigeon, and even the pigeon would have trouble stretching its beak around the biggest fruit. Pigeons are known to eat the fruit, but most of the fruit in Auckland falls off the trees and rots on the ground.
The tree itself can be 15 m tall with a trunk of up to 60 cm in diameter. The leaves are large ovals, generally 10 to 15 cm long, but sometimes up to 20 cm long, and 5 to 7 cm wide.
Distribution: Karaka is a coastal tree of the North Island but can be found as far South as Westport and Banks Peninsula. It is often found in groves because the Maori planted it for the fruit and the leaves.(4) Maori legend maintains that the karaka tree was brought to New Zealand by the early Maoris from their homeland, the legendary Hawaiki, but that doesn't fit the known distribution of the genus. It seems more probable that Hawaiki had a tree that looked rather similar to karaka. (1)(7)
Uses: The Maori called karaka fruit kopia and prepared it for food. It was greatly valued as food, second only to kumara and more important than bracken fern (7)(6). The outer fleshy layer of the kopia is edible without treatment, it tastes rather like overripe powdery apricot. The kernel of the seed was actually more important to the Maori, but it is extremely toxic and needs a great deal of preparation before it can be safely eaten. Eating the untreated kernel causes severe muscle cramps that can even rip the muscles off the bone.
The kernels have to be boiled and then steamed or soaked in running water before the poisonous karakin is completely leached out. The Maori ground the kernels up, after treatment, into flour for bread. This bread usually was reserved for the chiefs and other important people because of the amount of work involved in making it (7). The treated kernel has a nutty flavour after treatment. (1)(3)(4)(5)
The leaves were used to help wounds heal and to draw the poisons from a boil. The leaves were also made into coronets to wear on the head when visiting graves or during a tangi (Maori burial). (4)
The timber is white and very brittle and makes good firewood when dry, but has no other uses, although it was once used by Maoris for making canoes. (2)
References:
(1) J.T. Salmon (1989) The native trees of New Zealand.
(2) J.W. Matthews (1962) New Zealand trees. A popular guide to identification of the principal species.
(3) Gwen Skinner (1993) Simply living. A gatherer's guide to New Zealand's fields, forests and shores.
(4) Christina Macdonald (1979) Medicines of the Maori.
(5) Elsdon Best (1977) Forest lore of the Maori.
(6) Audrey Eagle (1978) Eagle's 100 trees of New Zealand.
(7) Mona Gordon (date?) The garden of Tane.
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