Prumnopitys taxifolia, commonly known as mataī and black pine, is a species of tree in the family Podocarpaceae. It is a dioecious evergreen conifer reaching 30 metres (100 feet) in height, with a stout trunk up to 2 m (6 ft 7 in) in diameter, typically inhabiting lowland to montane forests. It is endemic to New Zealand; its range mainly covers the North and South Islands, it is also found on Stewart Island, but is uncommon there. P. taxifolia is a slow-growing tree and is highly shade-tolerant. P. taxifolia is profoundly heteroblastic; its young form is distinct and resembles a divaricating-wiry shrub, which may last for up to 60 years. It is unknown why P. taxifolia developed this characteristic. P. taxifolia has an average lifespan of 600 years, although it sometimes may live longer than 1000 years. Prumnopitys taxifolia was first described by the British botanist Aylmer Bourke Lambert in 1832. The fruits of P. taxifolia are dispersed by fruit-eating animals (frugivores), and the tree is pollinated by the wind. It is common on fertile and well-drained soils, although it can still grow well in drier climates. P. taxifolia's timber is noted for its strength and durability, and was historically used for building bridges and houses, railway sleepers, and furniture-making. The conservation status of P. taxifolia was assessed by the IUCN Red List in 2013 as "Least Concern".
Description
Prumnopitys taxifolia is a species of dioecious evergreen conifer in the family Podocarpaceae, reaching heights of 30 metres (100 feet), with a stout trunk of up to 1–2 metres (3 feet 3 inches – 6 feet 7 inches) in diameter. Branches are initially ascending and eventually become spreading, forming a domed or rounded crown. The bark is thin and smooth (particularly on younger trees); it has spots, similar to hammer marks, which are red or purplish-brown in colour when fresh, weathering into a dark brown to black colour, and peeling freely into thick flakes. The outer bark itself can vary in colour from a dark brown to an almost black colour. The wood is very dense, hard, and has a dark brown to a yellow-brown colour. P. taxifolia has an average lifespan of 600 years, although a specimen from Tongariro National Park is estimated to have lived for more than 1000 years. Prumnopitys taxifolia's young form is distinct and the species profoundly exhibits heteroblasty (a significant change in a plant's form). Its young form, resembles a tangled shrub, is so distinct that the first botanists in New Zealand initially thought they were separate species. Unlike the related miro (Pectinopitys ferruginea), P. taxifolia has a distinctive and long-lasting young stage, which is a tangle of slender, flexible, divaricating branchlets. After several decades, the plant begins to grow out of the young shrub and the divaricating branchlets will drop off. It is unknown why this species developed this characteristic; one possibility is that the tangled branches are designed to create a warm temperature inside the shrub, hence the species could survive in colder climates, or it may serve as a defence against browsing animals. The young stage can last for up to 60 years. Young leaves are 5–10 × 1–2 mm long and brown to pale yellow in colour, narrow and tapering, with a pointed tip, and they can have long whip-like shoots. Adult leaves are 10–15 × 1–2 mm long, dark green in colour, glaucous, subdistichous and often apiculate in character. They generally have a broad shape, but can be more pectinate in character, and are (6–)10–20 mm long, (1–)1.5–2 mm wide. Leaves are widest near the middle, with nearly parallel sides. The midrib is raised on a bluish-green surface, where there are waxy, pale bluish-green bands of stomata. The Canadian botanist, James Emory Eckenwalder, suggested that the leaves of P. taxifolia potentially contain unidentified physiologically active compounds. Like all conifers, P. taxifolia does not produce flowers or true fruits, but instead produces pollen and seed in cones, or 'pseudo-fruits'. The species is dioecious, with male and female reproductive structures on separate trees. The ovules are found on short axillary branches, with 3–10 per a 40 mm long spike. P. taxifolia's male pollen cones are found on nearly leafless lateral and axillary spikes near the ends of foliage branches. Each spike is yellow in colour, and can have up to 10–30 cones per spike, each 5–12 mm long and approximately 2 mm wide. The seed cones take 12–18 months to mature and are found throughout the year. They are round to oval in shape, fleshy, globe-shaped or nearly spherical, purplish-black in colour, and about 8–10 mm wide. P. taxifolia has a diploid chromosome count of 38.
Phytochemistry The sap of P. taxifolia contains matairesinol, a compound which has been investigated in cancer research. In addition to matairesinol, the heartwood of the tree contains numerous other compounds, which includes, but is not limited to aromadendrin, kaempferol, quercetin, and genistein. Foliage oils of the tree were investigated in 1987 in the scientific journal Phytochemistry. Researchers found 7 sesquiterpene hydrocarbons and 2 oxygenated sesquiterpenes, 10 diterpene hydrocarbons, and 2 oxygenated diterpenes (including ferruginol) were identified.
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Taxonomy
Classification
Prumnopitys taxifolia is a member of the genus Prumnopitys, which consists of five species across Australasia and South America. P. taxifolia is categorised in the subgenus Prumnopitys. In 2019 the British botanist Chris Page transferred six species from Prumnopitys into a genus Page newly described as Pectinopitys. Page retained three species within the genus Prumnopitys, including P. taxifolia. He based his move on cladistic, morphological, and molecular analysis, concluding that Pectinopitys was distinct enough for it to be described as a new genus, rather than retaining it in Prumnopitys. Page also mentioned that Pectinopitys has a diploid chromosome count of 2n = 36, while Prumnopitys has a count of 2n = 38. Khan et al. (2022) reported that Prumnopitys montana of South America, is the closest relative to P. taxifolia. A 2012 study based on rbcL data sequencing revealed that both species are nearly allied to species within the genus Pectinopitys (formerly placed within the same genus).
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