Araucaria heterophylla
Araucaria heterophylla | |
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Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Gymnospermae |
Division: | Pinophyta |
Class: | Pinopsida |
Order: | Araucariales
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Family: | Araucariaceae |
Genus: | Araucaria |
Section: | A. sect. Eutacta |
Species: | A. heterophylla
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Binomial name | |
Araucaria heterophylla (Salisb.) Franco
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Synonyms | |
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Araucaria heterophylla (synonym A. excelsa) is a species of
History
The first European known to have sighted Norfolk Island was Captain James Cook. In 1774, on his second voyage to the South Pacific in HMS Resolution, Cook noted the presence of large forests of tall, straight trees that appeared to be suitable for use as masts and yards for sailing ships. However, when the island was occupied in 1788 by convicts transported from Britain, it was found that Norfolk Island pine trees were not resilient enough for such use and the idea was abandoned.[2]
In the late 1950s, a trial shipment of Norfolk pine logs was sent to plywood manufacturers in Sydney, New South Wales, with the hope of developing a timber export industry on Norfolk Island. Although the plywood companies reported excellent results, the industry was deemed not
Description
The tree is slow growing and can reach a height of 50–65 m (160–210 ft), 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 five almost horizontal or slightly oblique branches, 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. The branchlets are four to seven in regular whorls.
The young
The scientific name heterophylla ("different leaves") derives from the variation in the leaves between young and adult plants.
Cultivation
The distinctive appearance of this tree, with its widely spaced branches and symmetrical, triangular outline, has made it a popular cultivated species, either as a single tree or in avenues. When the tree reaches maturity, the shape may become less symmetrical. Despite the endemic implication of the species name Norfolk Island pine, the species is widely planted as an ornamental tree for its exotic, pleasing appearance and fairly broad climatic adaptability, and now occurs throughout the world in regions with suitable Mediterranean and humid subtropical climate. It grows well in deep sand, as long as it receives reliable water when young. This, and its tolerance of salt and wind, make it ideal for coastal situations. Indoors, the plant needs a bright location with at least 40% but preferably above 60% humidity for good growth. Indoor trees must not be exposed to the scorching sun or dry air from a radiator; the temperature should ideally not exceed 22 °C (72 °F). In winter, the plant needs a bright room that should be around 17 °C (63 °F).[3]
Many of the "Norfolk Island pines" that grow in Hawaii, including their descendants used as potted ornamentals on the U.S. mainland, are actually the closely related
Uses
Young trees are often grown as
Large numbers of Norfolk Island pines are produced in
When planted outside, the trees should be provided with adequate space, as they can grow to a large size. The trees are widely planted in South Florida where they generally stay below 30 m (100 feet) in height,[6] and in coastal Southern California where they can grow to well over 30 m (100 feet).[7]
Araucaria heterophylla has gained the Royal Horticultural Society's Award of Garden Merit.[8]
Conservation and weediness
The species survival is not threatened at all by the houseplant trade, as it is grown commercially for potted plants. However, the native, natural stands of A. heterophylla were always restricted and have been much reduced since Capt. Cook's time. Farming, poor land management and the introduction of invasive species have reduced its population on the original three islands considerably. The main remaining stands are now within Norfolk Island National park and are therefore under some shelter. The
Gallery
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Cones and foliage
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Foliage from a mature tree
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Specimen growing in the Abbey Gardens on Tresco, Isles of Scilly. These are amongst the most northerly specimens that are grown outdoors.
References
- ^ . Retrieved 19 November 2021.
- ISBN 0-394-75366-6.
- ^ "Norfolk Island Weather". www.discovernorfolkisland.com. Retrieved 15 October 2022.
- ^ Armstrong, Wayne P. "The Araucaria Family: Past & Present". Pacific Horticulture Society. Retrieved 6 March 2021.
- ^ Nelson, Jennifer Schultz (12 January 2017). "3 Keys to a Healthy Norfolk Island Pine". Grounded and Growing. Retrieved 29 November 2019.
- ^ "Norfolk Island Pine". University of Florida. Retrieved 18 May 2022.
- ^ "Araucaria heterophylla Tree Record". SelecTree. UFEI. 1995-2022. Cal Poly State University, San Luis Obispo. Retrieved 18 May 2022.
- ^ "RHS Plantfinder - Araucaria heterophylla". Royal Horticultural Society. Retrieved 12 January 2018.