It is a slow growing tree, reaching a height of 50m–65 m, with straight vertical trunks and symmetrical branches, even in the face of incessant onshore winds that can contort most other species. From the straight trunk, it emits its branches almost horizontal or slightly oblique, in number of five, forming floors; the plane of each floor is a perfect pentagon. If kept indoors, the tree remains smaller. The gray-brown bark falls off in fine scales. At the more or less horizontal to sometimes hanging branches, the branches are four to seven in regular whorls. The young leaves are soft and awl-shaped, 1–1.5 cm long, about 1 mm thick at the base on young trees, and incurved, 5–10 mm long and variably 2–4 mm broad on older trees. The thickest, scale-like leaves on coning branches are in the upper crown. The cones are squat globose, 10–12 cm long and 12–14 cm diameter, and take about 18 months to mature. They disintegrate at maturity to release the nut-like edible seeds. The seeds have a length of 2.5 to 3 cm and a diameter of about 1.2 cm with wide wings. There are four cotyledons present. It is a dioecious tree (male and female flowers in different plants), although it can also be monoecious. The scientific name heterophylla ("different leaves") derives from the variation in the leaves between young and adult plants.
Norfolk Island pine's facts
Did you know?
Scientific research by NASA showed that Norfolk Island pines can remove harmful VOCs (volatile organic compounds) from the air, purifying it and making it safer for you and your family to breathe.
Norfolk Island pine's Behavior & Ecology
The plant loves direct sunlight, a tropical climate and requires a well-drained soil. Many of the best common house plants have the same requirements.
Norfolk Island pine's Reproduction
Propagation: Seed and Cuttings.
Note:- cuttings taken from vigorous upright material will inherit normal upright growth habit, whilst cuttings taken from horizontal branches will root, but will maintain their horizontal growth habit rather than normal upright growth.
Norfolk Island pine's Relationship with Humans
The wood of large trees is used in construction, furniture, and shipbuilding. The plant is grown as an outdoor ornamental in regions with a Mediterranean climate, and the attractive saplings are cultivated throughout the world as houseplants.
Norfolk Island pine habitat
The original vegetation on Norfolk Island was an evergreen subtropical forest with angiosperm trees and tree ferns 10-20 m high, over which A. heterophylla emerged at least 30 m and occasionally taller. The really large trees have all been felled, but evidence of trees with a diameter at breast height (d.b.h.) of around 3 m still existed in the 1920s and large trees have now again reached in excess of 1 m d.b.h. and 35-40 m height. Common angiosperm trees are (were) Olea apetala Vahl (Oleaceae), Elaeodendron curtipendulum Endl. (Celastraceae), Celtis paniculata (Endl.) Planch. (Ulmaceae), Streblus pendulinus (Endl.) F.Muell. (Moraceae), Lagunaria patersonia (Andrews) G.Don (Malvaceae), Acronychia simplicifolia (Endl.) Steud. and Zanthoxylum blackburnia Benth. (Rutaceae), Rhopalostylis baueri H.Wendl. & Drude (Arecaceae), Meryta angustifolia (Araliaceae), Baloghia inophylla (G.Forst.) P.S.Green (Euphorbiaceae) and Dysoxylum patersoni F.Muell. (Meliaceae) as well as the tree ferns Cyathea australis (R.Br.) Domin and C. brownii Domin (Cyatheaceae). This type of forest is now fragmented and very restricted in its distribution on Norfolk Island. Araucaria heterophylla also persists as solitary trees on coastal headlands or in groves with a low undergrowth of mostly grasses or of open scrub, with many introduced species.
Norfolk Island pine threats
Logging has been a threat in the past. Land clearance and grazing have also been significant threats in the past but are now less problematic. The impact of introduced invasive species has been significant: rabbits, goats and pigs were responsible for the loss of almost all vegetation on Phillip Island while exotic trees such as Psidium cattleianum and Olea europaea ssp. cuspidata have colonised many areas on Norfolk Island itself to form dense impenetrable thickets. In the 1970s many Araucarias suffered from a dieback that was associated with habitat degradation and adverse environmental conditions. Improvements in land management practices, the introduction of a biological control and the removal of invasive species have led to a lessening of this problem although invasive species are still a major and ongoing threat.