Chatham Island Karamū

Botanical name: Coprosma chathamica
Synonyms: None known
Common name(s): Chatham Island Karamū, Karamū

About:
A handsome evergreen canopy tree endemic to the Chatham Islands, valued for its glossy dark green leaves, yellow to orange fruit and adaptability to wet coastal forests. It is one of the principal forest trees of the Chatham Islands and plays an important role in the structure and ecology of these unique island ecosystems. Juvenile plants have strikingly large leaves, while mature trees develop smaller, glossy foliage and a broad spreading crown.

Natural habitat:
Coastal and inland forests of the Chatham Islands, growing on peat soils, seasonally waterlogged sites, limestone outcrops, basalt and schist substrates.

Growing environment:
Prefers moist, fertile soils and tolerates periodic waterlogging. Grows best in full sun to partial shade and withstands wind and salt exposure. Also performs well in free-draining soils provided moisture is available.

Endemic distribution:
Endemic to the Chatham Islands group, occurring naturally on Rekohu (Chatham Island), Rangiauria (Pitt Island) and Rangatira (South East Island).

Height:
Up to 15 m in the wild, typically 3–6 m in cultivation

Width:
2–6 m

Flowering:
August–December

Fruiting:
November–May

Uses:
• Coastal and wetland restoration
• Specimen tree for large gardens
• Shelter and habitat for native wildlife
• Forest restoration projects
• Native and island-themed gardens
• Cultural and ecological plantings

Appearance:

Growth habit:
A medium to large evergreen tree with a stout trunk up to 600 mm in diameter and a dense crown of spreading branches. Young branchlets are stout and covered in fine hairs.

Leaves:
Juvenile leaves are large, broadly ovate and often have hairy margins, measuring 45–75 mm long. Adult leaves are much smaller, 20–35 mm long, dark green and glossy above with paler undersides. They are ovate to elliptic with slightly wavy margins and a small pointed tip. The veins are more obvious on the lower surface and often have small pits where veins meet.

Flowers:
Small green flowers are produced from late winter through spring. Male flowers occur singly or in small clusters, while female flowers are borne in groups of one to six. Flowers are inconspicuous but abundant.

Fruit:
The fruit is an attractive fleshy drupe, yellow to orange or yellow-red when ripe. It is slightly flattened, oval to obovoid and measures approximately 9–14 mm across.

Ecology:
The fleshy fruit is eaten and dispersed by birds. Chatham Island Karamū is one of the dominant canopy species of the Chatham Islands and forms extensive forests with species such as swamp akeake, Chatham Island matipo and tarahinau. It provides habitat for numerous native insects, including longhorn beetles, and is an important host for several endemic lichens.

Associated habitats:
Coastal forest, peat swamp forest, inland forest, dune forest, basalt and schist outcrops, tarahinau forest and swamp akeake forest.

How to grow:
Plant in full sun or partial shade in moist, fertile soil. It tolerates periodic waterlogging and coastal conditions but requires space to develop into a mature tree. Water regularly during establishment and mulch to maintain soil moisture.

Propagation:
Easily grown from fresh seed or semi-hardwood cuttings. Seed germinates readily when sown fresh. Cuttings root best under warm, humid conditions.

Cultural use:
Traditionally important to the Moriori people. The tree was used in funerary rites, where vines or stems were used to bind the deceased upright facing the sea, with the remains gradually becoming incorporated into the living tree. It remains an important symbol of the natural and cultural heritage of the Chatham Islands.

Garden value:
A striking and unusual tree that combines glossy foliage, colourful fruit and excellent tolerance of wet or coastal conditions. Ideal for larger native gardens, wetland plantings and collections featuring Chatham Islands flora.