User:Dracophyllum/Dacrydium cupressinum

Rimu
Conservation status
	; Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Gymnospermae
Division:	Pinophyta
Class:	Pinopsida
Order:	Araucariales
Family:	Podocarpaceae
Genus:	Dacrydium
Species:	D. cupressinum
Binomial name
	Dacrydium cupressinum; Sol. ex Lamb.
	Natural range of D. cupressinum
Synonyms
	Thalamia cupressina Spreng

Dacrydium cupressinum, commonly known as rimu (from Māori) or red pine, is a coniferous tree endemic to New Zealand. A podocarp, it can grow to heights of 60 m over a life span of up to more than 1000 years. It was first described botanically in 1786 by Daniel Solander and later given a full description by Aylmer Lambert. One of New Zealand's most common forest trees, it grows in a variety of habitats in the North, South, and Stewart Islands.

Rimu seeds are mostly dispersed by birds such as kererū, tūī and bellbirds, and the fruit provide a key source of food for the endangered bird the kākāpō, which will only mate during years of heavy fruiting. Curabitur sagittis est quis sem placerat, nec consectetur quam gravida. Morbi sit amet mi tempus, vulputate tellus ut, auctor neque. Suspendisse potenti. Aenean id lorem velit. Donec vitae semper ex. Sed viverra diam nec mollis bibendum.

Description

The rimu is a coniferous tree that reaches a height of 35–60 m (115–197 ft), with a trunk 1.5–2 m (4.9–6.6 ft) in diameter. A dark-brown and flaky bark covers the trunk. The wood is a dark red colour. In its juvenile stages the branches are thin and numerous, but as the tree grows older three quarters of the tree becomes branchless.^[2] It has a lifespan of 600–800 years, but may reach beyond 1000 in rare cases.^[3]

The yellowish-green foliage varies in size and shape between the juvenile, sub-adult, and adult life stages. The leaves begin 0.4–10 mm long and 0.5–0.1 mm wide with sharp points. They are divided along an axis and roughly shaped like a sickle. In sub-adults the leaves shorten to 4–6 mm long, curve upward, and become diamond shaped. In adults the leaves become smaller, just 2–3 mm long and press against one-another tightly.^[2]

Male and female cones, or strobili, appear first in sub-adults but on different male and female trees. Male cones are 5–10 mm long, rectangular shaped, and covered in a yellow pollen. Ovules appear solitary on upturning branchlets. Fruit is formed of a 1–2 mm long fleshy and orange receptacle, with a 3–4 mm long dark brown rectangular-shaped seed attached. It is distinctive enough that it is unlikely to be misidentified except with Manoao colensoi seedlings, which have glossier, less fine leaves. The rimu has a diploid chromosome count of 20.^[2]

Bark
Male cones
Fruit

Taxonomy

The rimu was first described in 1786 by Daniel Solander and Georg Forster as Dacrydium cupressinum in their De Plantis Esculentis Insularum Oceani Australis Commentatio Botanica.^[4] A full description was given by Aylmer Lambert in his 1803 A description of the genus Pinus.^[5] It was superfluously given the name Thalamia cupressina by Kurt Sprengel in an 1826 volume of Systema Vegetabilium.^[6]

Dacrydium means "tear drop" and the specific epithet cupressinum references plants in the Cupressaceae family. Common names include rimu, from the Māori language, and red pine.^[2]

Evolution

The evolution of the rimu was analysed in a 1998 paper on the phylogeny of the wider Podocarp family, which found it to be sister to a clade containing other podocarp species including those in the genus Dacrycarpus. This demonstrated that it both shares a common ancestor with those species and is yet evolutionarily distinct.^[7] This can be demonstrated in the simplified cladogram below.

Podocarp sp.

Podocarpus totara

	Dacrycarpus imbricatus

	Dacrycarpus dacrydioides

Dacrydium cupressinum

https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1096-0031.2011.00381.x

Distribution

The rimu grows throughout New Zealand, in the North, South, and Stewart Islands.^[2] It is common in a variety of lowland and montane forests across New Zealand, only becoming uncommon in Malborough and Cantebury, as well as inland Otago and Southland. In the North Island it grows from sea level to 950 m (3,120 ft), compared to around 500 m (1,600 ft) in Fiordland. The rimu will not grow in areas with limited rainfall or where snow cover is persistent.^[8]

Ecology

The endemic and flightless New Zealand bird the kākāpō (Strigops habroptilus) mates only in years in which rimu fruit heavily, called mast years.^[9]

Dispersal

Rimu seeds are primarily dispersed by birds, such as the tūī and bellbird in the North Island and the kererū in the South Island. They eat both the seed and the fleshy receptacle but do not digest the seed, allowing it to pass through and be dispersed. Wind or gravity dispersal is inefficient, only leaving the seeds typically just 10 m away from the tree. Seeds have been recorded being destroyed by wētā, rats, mice and chaffinches.^[8]

https://www-tandfonline-com.wikipedialibrary.idm.oclc.org/doi/full/10.1080/0028825X.2011.643474 (fungi)

https://www.sciencedirect.com/science/article/abs/pii/S1433831909000237

Uses

Māori originally used the resinous heartwood of rimu (called māpara or kāpara) for wooden items such as heru (combs) and fernroot beaters.^[10]^[11] Historically, rimu and other native trees such as kauri, matai 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. There is also limited recovery of stump and root wood, from trees felled many years before, for use in making bowls and other wood turned objects.

The inner bark can also be used to treat burns and cuts.^[12]

Cultivation

Although slow to establish, with a long juvenile period and fairly high moisture requirements, rimu is widely grown as an ornamental tree in New Zealand. It is attractive at all growth stages, usually quite narrow when young, then developing into a broader tree with weeping branches before finally progressing to its more upright adult form. While rimu does exhibit some variation in the wild, garden cultivars are largely unknown, except for one recent introduction, 'Charisma', which is a compact, golden-foliaged form.