Dacrydium cupressinum

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Dacrydium cupressinum
Juvenile Rimu foliage
Juvenile Rimu foliage
Conservation status
Scientific classification
Kingdom: Plantae
Division: Pinophyta
Class: Pinopsida
Order: Pinales
Family: Podocarpaceae
Genus: Dacrydium
Species: D. cupressinum
Binomial name
Dacrydium cupressinum
Sol. ex Lamb.

Dacrydium cupressinum (Rimu) is a large evergreen coniferous tree endemic to the forests of New Zealand. It was formerly known as "red pine" by the European colonists, although this name is misleading since it is not a true pine but a member of the southern conifer group the podocarps. Red pine has fallen out of common use and the Māori name Rimu is now used.

The characteristic scale-like bark of the Rimu
Delicate, awl-shaped leaves

Rimu grows throughout New Zealand, in the North Island, South Island and Stewart Island/Rakiura. Although the largest concentration of trees is now found on the West Coast of the South Island, the biggest trees tend to be in mixed podocarp forest near Taupo (e.g., Pureora, Waihaha, and Whirinaki Forests).

It can be a large but slow-growing tree, growing as high as 50 m tall, though most surviving large trees are 20 to 35 m tall. It typically appears as an emergent from mixed broadleaf temperate rainforest, although there are almost pure stands (especially the west coast of the South Island). There are historical accounts of exceptionally tall trees, ~60 m, from dense forest near National Park, New Zealand, now destroyed. Its lifespan is approximately 800 to 900 years. Diameters of these trees may exceed 2 m at breast height.

The leaves are spirally arranged, awl-shaped, 3 to 6 mm long on juvenile plants, and 2 to 3 mm long on mature trees. It is dioecious, with male and female cones on separate trees; the seeds take 15 months to mature after pollination. The mature cones comprise a swollen red fleshy scale 6 to 10 mm long bearing one (rarely two) apical seeds 4 mm long. The seeds are dispersed by birds which eat the fleshy scale and pass the seed on in their droppings; they are an important food resource for some species, particularly the Kakapo, whose breeding cycle has been linked to rimu's cone production cycle.

Uses

Historically, Rimu and other native trees such as Kauri and Totara were the main sources of wood for New Zealand, including furniture and house construction. However, many of New Zealand's original stands of Rimu have been destroyed, and recent government policies forbid the felling of Rimu in public forests, though allowing limited logging on private land. Pinus radiata has now replaced Rimu in most industries, although Rimu remains popular for the production of high quality wooden furniture.

References