Meryta is a genus of approximately 28 described species of small, resinous trees in the family Araliaceae (order Apiales), native to the subtropical and tropical Pacific Ocean. The genus is distinguished within Araliaceae by an unusual combination: enormous, simple leaves paired with a dioecious sexual system (separate male and female plants), a pairing found in no other member of the family. Individual trees typically develop stout, brittle-branched trunks with leaves crowded at the tips of branchlets; leaves can reach 50 cm or more in length on petioles up to 35 cm, with a coriaceous, glossy surface and slightly undulate margins.
The center of diversity lies in New Caledonia, which harbors 11 endemic species. Other species occur across the wider Pacific, including Norfolk Island, the Three Kings Islands of northern New Zealand, and various tropical island groups. Phylogenetic analyses place Meryta as a monophyletic genus within the Polyscias-Pseudopanax group — one of the three major clades of Araliaceae — and more specifically within the Pacific Schefflera subclade.
The best-known species in cultivation is Meryta sinclairii (pukanui or puka), endemic to the Three Kings Islands of New Zealand, where it is the dominant canopy tree. It is widely grown in northern New Zealand and elsewhere in mild-temperate and subtropical regions for its dramatic, large glossy foliage. Meryta denhamii and M. latifolia from New Caledonia and Norfolk Island respectively are also cultivated for ornamental use. Most species tolerate coastal conditions well.
Etymology
The genus name Meryta derives from a Greek word meaning "rolled up," likely referring to the texture or vernation of the distinctive large leaves. The epithet of the most familiar species, M. sinclairii, honours Andrew Sinclair (c. 1796–1861), Colonial Secretary of New Zealand and a keen naturalist.
Distribution
Meryta species are native to subtropical and tropical islands of the Pacific Ocean, with the greatest concentration of species (11 endemics) in New Caledonia. Additional species occur on Norfolk Island, the Three Kings Islands of northern New Zealand, and other Pacific island groups. Meryta sinclairii is restricted in the wild to the Three Kings Islands, where it is the dominant tree, though it has been introduced to the Hen and Chickens Islands and is widely cultivated in northern New Zealand.
Ecology
In its native Three Kings Islands habitat, Meryta sinclairii dominates coastal forest, grassland, and scrub, giving way only to taller kānuka-dominated forest on Great Island. The genus as a whole occupies coastal and lowland forest habitats across the Pacific. As dioecious trees, all Meryta species require both male and female individuals for reproduction and fruit set.
Cultivation
Meryta species can be grown in tropical, subtropical, and mild-temperate coastal climates, where they are valued for their dramatic, large glossy leaves. Meryta sinclairii is easily grown from fresh seed, which often germinates naturally beneath parent trees. Plants perform best in free-draining soil in a coastal situation. They are prone to phytophthora and verticillium wilt, for which no reliable treatment is available. M. denhamii and M. latifolia are also encountered in cultivation.
Conservation
Meryta sinclairii is assessed as "At Risk – Naturally Uncommon" under the New Zealand Threat Classification System (2023 assessment). Although it is abundant across the Three Kings Islands, its restricted range makes it vulnerable to the introduction of soil-borne fungal pathogens and rodents — both threats associated with increasing human activity on remote offshore islands. Regular monitoring by the New Zealand Department of Conservation is critical to maintaining populations.
