Rimu and kahikatea were once widespread in lowland forest, but both have been extensively milled for their valuable timbers. They belong to New Zealand’s largest conifer family, the podocarps – a group that does not have woody cones. Instead, their female cones are reduced to single scales that ripen into solitary seeds surrounded by or sitting on brightly coloured, fleshy structures that attract birds.
Rimu (Dacrydium cupressinum) is the commonest and most widely distributed conifer in New Zealand, growing from Northland down to Stewart Island. It is a tall tree, and its crown usually emerges above the main canopy of forest trees. On well-drained fertile sites, it grows to 50 metres in height. Rimu usually favours better drained sites than kahikatea, but does grow in poorly drained soils in Westland.
Rimu can live for more than 1,000 years. A life-span of 550–650 years is more common, as old trees become susceptible to uprooting in strong winds. Seedlings will not grow in deep shade or on open, exposed sites. Mature trees often support a crop of perching plants on their upper branches. For example, northern rātā often starts life as a young seedling high up in the crown of a mature rimu.
When young, rimu has weeping branchlets, but these become long, drooping branches when the tree matures. Its leaves are small, scale-like, and yellow-green. When fully grown it sheds large flakes of bark, leaving a wavy pattern on the trunk.
Pollen and seeds are produced by male and female trees respectively. Seeds take about 18 months to ripen. Each black seed sits on a red, fleshy receptacle which is eaten by birds or falls to the ground. Heavy seed crops occur every few years.
Rimu was the principal native tree milled following European settlement. Peak production occurred just after the Second World War, to meet the great demand for new houses. The reddish-brown timber was used for framing, weatherboards, flooring, doors and panelling. Today, recycled rimu is popular for furniture.
Beer from the branches
James Cook’s crew made rimu beer when they were at Dusky Sound, Fiordland, in March 1773:
Make a strong brew of water and small branches of rimu
and mānuka, boiling for two to four hours, or until the
bark strips off the branches easily.
Take the branches out of the copper and put in molasses or sugar, 10 gallons of molasses to 240 gallons of beer. Bring the brew back to boil, then put it into casks with an equal quantity of cold water. When the whole is milk-warm, add yeast and leave for a few days. 1
New Zealand’s tallest tree, kahikatea (Dacrycarpus dacrydioides), reaches 60 metres in height. It grows throughout New Zealand on moist, fertile soils, and is the dominant tree of swampy lowland areas. Today, kahikatea grows in fewer places than it did at the time of European settlement, as the land it grew on made productive farmland.
Seedling foliage consists of narrow little leaves, lying flat in two rows on thin branches. Adults have scale-leaves, similar to those of rimu, but often bright green or blue-green. Kahikatea has ascending branchlets, in marked contrast to rimu’s long weeping branchlets.
Kahikatea has separate male and female trees. It produces purple-black seeds above a fleshy orange-red stalk. Like rimu, it has good and poor seed years. Tūī, bellbirds, kākā and kererū disperse the seeds. Its seedlings need a lot of sunlight, and grow fastest in the open or lightly shaded sites.
The creamy-white wood of kahikatea is light and easily worked, but not durable. It was used for canoes by Māori, and with a plentiful supply of kahikatea growing on stream and river banks there was no shortage of suitable trunks to choose from.
Kahikatea forests were felled to provide valuable land for dairy farming in the late 19th and early 20th centuries. The forests also provided the containers in which dairy products were exported to Britain. Because kahikatea wood is odourless and does not taint butter or cheese, a large number of trees were milled and turned into butter boxes and cheese crates. Kahikatea timber was also used for fascia boards on houses, scaffold planks, and for boat building.