Common name: Rimu
Taxonomy
- Kingdom: Plantae
- Clade: Tracheophytes
- Clade: Gymnosperms
- Order: Pinales
- Family: Podocarpaceae
- Genus: Dacrydium
- Species: D. cupressinum
Description
Dacrydium cupressinum is a large evergreen coniferous tree endemic to New Zealand. Mature individuals typically reach heights of 30–50 m, with some exceptional specimens exceeding 70 m. The trunk is straight and may attain diameters up to 2 m. Bark is brown to reddish‑brown, peeling in thin strips. Leaves are narrow, linear, and glossy, measuring 5–10 mm in length; they are arranged spirally around the shoots. The species is dioecious, bearing male and female reproductive structures on separate trees. Male cones are small, cylindrical, and release pollen in the spring. Female cones develop into fleshy, berry‑like arils that mature to a dark purple‑black colour, each containing a single seed.
Distribution and Habitat
D. cupressinum occurs throughout the main islands of New Zealand, from lowland coastal forests to subalpine regions up to approximately 1,000 m elevation. It favors damp, well‑drained soils and is a prominent component of mixed podocarp‑broadleaf forests. The species tolerates a range of climatic conditions but is most abundant in regions with high rainfall.
Ecology
The arils are an important food source for native birds, including the kererū (Hemiphaga novaeseelandiae) and the tūī (Prosthemadera novaeseelandiae), which aid in seed dispersal. Rimu wood provides structural habitat for epiphytic lichens and mosses. The tree also contributes to forest carbon storage and water regulation.
Uses
Historically, the timber of D. cupressinum was logged for construction, flooring, and furniture due to its strength, durability, and attractive grain. In contemporary practice, the species is protected in many areas, and any timber extraction is subject to strict management regulations. The wood is also used in specialty applications such as musical instrument making.
Conservation Status
The International Union for Conservation of Nature (IUCN) lists Dacrydium cupressinum as Least Concern. While the species remains relatively common, past extensive logging reduced its abundance in some regions. Ongoing conservation measures include protected forest reserves, sustainable forest management certifications, and restoration planting programs.
Cultural Significance
Rimu holds cultural importance for Māori, who traditionally used the wood for building waka (canoes) and carving. The tree is also featured in Māori proverbs and place names.
References
- New Zealand Plant Conservation Network. “Rimu (Dacrydium cupressinum)”.
- IUCN Red List of Threatened Species. “Dacrydium cupressinum”.
- de Lange, P.J.; Worthley, H.P. (1991). The native flora of New Zealand. Oxford University Press.
