Dacrydium cupressinum

Dacrydium cupressinum bark

Dacrydium cupressinum male cones

Dacrydium cupressinum fruit

Dacrydium cupressinum, commonly known as rimu, is a large evergreen coniferous tree endemic to the forests of New Zealand. It is a member of the family Podocarpaceae, which includes other notable trees such as the kauri (Agathis species) and totara (Podocarpus species). Rimu plays a significant role in New Zealand's natural and cultural heritage, being one of the most widespread and commercially important native trees in the country.

Description

Dacrydium cupressinum can grow up to 50 meters in height, with a trunk diameter of up to 1.5 meters. The tree's bark is thick and flaky, peeling off in large chunks. Rimu has a distinctive growth pattern; young trees have a narrow, conical shape which becomes more irregular with age. The leaves are small, needle-like, and attached directly to the branches in spiral patterns. In mature trees, the lower branches often droop towards the ground.

Rimu produces separate male and female cones on the same tree (monoecious). The female cones are highly modified and resemble berries, turning red when ripe. These "fruits" are an important food source for many native birds, including the New Zealand pigeon (kererū) and the endangered kākāpō.

Distribution and Habitat

Dacrydium cupressinum is found throughout both the North and South Islands of New Zealand, from sea level up to the subalpine zone. It prefers wet, temperate rainforests but can also be found in drier mixed podocarp forests. Rimu is a key component of these forest ecosystems, often playing a role as a canopy or emergent layer tree.

Uses

Historically, rimu wood was highly valued for its strength, durability, and beauty. It was used extensively in construction, furniture, and flooring. The wood has a distinctive reddish hue and a fine grain, making it a popular choice for woodworking. However, due to overexploitation and conservation efforts, the use of rimu wood is now more regulated.

Rimu is also of cultural significance to the Māori, the indigenous people of New Zealand. It was used in traditional carvings and as a source of medicinal remedies. The tree's resin, known as "rimu gum," was applied as a waterproofing agent and for therapeutic purposes.

Conservation

The conservation status of Dacrydium cupressinum has been a concern due to historical logging and habitat destruction. Although it is not currently listed as endangered, rimu is protected in many areas within New Zealand's national parks and reserves. Conservation efforts focus on habitat preservation, sustainable management practices, and reforestation projects to ensure the survival of rimu populations.

See Also

• Podocarpaceae
• Flora of New Zealand
• Conservation in New Zealand