Araucaria cunninghamii

young and mature female cones

Hoop Pine

Araucaria cunninghamii Mudie

Araucaria cunninghamii, commonly known as the Hoop Pine, is a gymnosperm in the family Araucariaceae. The Araucariaceae consists of 38 species across the Pacific region and South America with 5 species occurring in Australia.

Araucaria cunninghamii is an adaptable tree that is capable of growing on a variety of soils provided the annual rainfall exceeds 30 inches. As a result, A. cunninghamii occurs in rainforests and rainforest edges along the east coast of Australia from the Macleay River in New South Wales up as far north as Cape York Peninsula and extending into PNG.

Araucaria cunninghamii is a symmetrical, cone-shaped tree that grows up to 60 m in height and gets its common name from the outer layer of bark which forms scale-like horizontal hoops. The branches are whorled and the leaves are very fine and pointy. It is a slow-growing plant that can live for up to 450 years. Because of its adaptability to a variety of conditions A. cunninghamii is an established commercial plantation tree throughout south-east Queensland.

Male and female cones of Araucaria cunninghamii are usually on the same tree, with male cones forming a dense cluster of cylindrical spikes. Trees are usually 22–27 years old before producing male (pollen) cones, although precocious pollen cone production has been observed in six-year-old individuals. Female (seed) cones are round and occur near the top of the tree; they have been observed on individuals as young as six years old but the more usual age of first seed cone production is around 10–12 years. Seeds are released with the cone scale on disintegration of the ripe female cones, which tends to occur from November to February. The female cones are brown when mature and about 8–10 cm in diameter. The position of these cones near the top of the tree enables the seeds to be dispersed by winds strong enough to displace them a viable distance from their parent.

Propagation of Araucaria cunninghamii is generally from seed but the use of cuttings is also possible. Seedlings should be transferred to tubes or pots after 12 months for further growth and may be planted once they reach two years old. Regular watering is essential for the first two years in the ground and a native plant potting mix can also be useful in aiding the early stages of development. Once properly established the tree is fairly resilient and will often continue to grow slowly provided it gets enough moisture. Cuttings may also be used but this method is less common and relatively unsuccessful. If cuttings are used they must be taken from upright growing shoots toward the tops of the tree.

Araucaria cunninghamii is a very attractive tree especially when planted in clusters as they give a grand look to any landscape. They are limited by space as they are such large trees and should be planted in subtropical climates for the best outcome.

Text by Andrew Gardiner (2014 Student Botanical Intern); since updated online.

References:

Department of Agriculture, Fisheries and Forestry, Qld, DAFF (2013) Hoop pine - Araucaria (plantations). Technical Report. DAFF, Qld. Available at http://era.deedi.qld.gov.au/3931/.

Elliot, W.R. & Jones, D.L. (1982) Encyclopaedia of Australian Plants Suitable for Cultivation, vol. 2. Lothian Publishing.

Floyd, A.G. (2008) Rainforest Trees of Mainland South-eastern Australia, The Channon: Rainforest Publishing.

Hall, N., Johnston, R.D. & Chippendale, G.M. (1970) Forest Trees of Australia, 3rd edn. Australian Govt. Pub. Service, ACT.

McMahon, M. (2014) Horticulturalist, ANBG. Personal communication.

Nikles, D.G., Dieters, M.J., Johnson, M.J., Setiawati, Y.G.B. & Doley, D.D. (2009) The reproductive biology of hoop pine (Araucaria cunninghamii Aiton ex D.Don) and its significance in a genetic improvement programme. pp. 157–165 in: R.L.Bieleski & M.D.Wilcox (eds), Araucariaceae: proceedings of the 2002 Araucariaceae Symposium, Araucaria-Agathis-Wollemia, International Dendrology Society, Auckland, New Zealand, 14–17 March 2002. International Dendrology Society, Dunedin, N.Z.

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