Araucaria bidwillii (Bunya Pine)
Michael's Opinion
Reaching a record height of 50 meters, with trunks like a Sauropod’s leg and sporting cones bigger than a bowling ball, immediately impressive, few things say ancient as the sight of a fully mature Bunya Pine.
Botanical Information
| Family | Araucariaceae |
| Genus | Araucaria |
| Species | bidwillii |
| Category | Tropicals, Woody |
| Type | Tree (evergreen) |
| Origin | Native to southeast Queensland, Australia and mostly found between Nambour and Gympie and west to the Bunya Mountains. The Bunya Pine can also be found growing in two small stands to the north of Queensland at Mt Lewis and Cannabullen Falls. |
| Ethnobotanical Uses Disclaimer | The Bunya nut has been a traditional food source for the Indigenous people of Australia for generations. The nutritious nut can be eaten raw, baked, boiled, and ground into flour. In cases where the nut has germinated, the tuber can be eaten. The timber of the Bunya Pine is ideal for acoustic musical instruments and since the mid 1990’s has been used for producing acoustic guitars. The soft, yellow, easily worked, and high-quality wood has also been used in the production furniture, flooring, and cabinetry for over a century. |
| Pronunciation |
Details
| USDA Hardiness Zone | 9 |
| USDA Hardiness Ref. | |
| Canadian Hardiness Zone | Requires cool season protection under glass |
| Canada Hardiness Ref. | |
| RHS Hardiness Zone | H1c |
| RHS Hardiness Ref. | |
| Temperature (°C) | (-4) - (40) |
| Temperature (°F) | 20 - 30 |
| Height | 30 - 45 m |
| Spread | 10 - 15 m |
| Growth | Slow |
| Flowering Period | April |
Description and Growing Information
| General Description | Araucaria bidwillii is a widely recognised Australian emergent conifer, celebrated for its incredible stature, delicious and nutritious seeds, enormous cones, as well as its cultural and evolutionary significance. Belonging to the Araucariaceae, one of the oldest surviving families of trees. The family was widespread in the Jurassic and Cretaceous periods, but today Araucaria budwillii is endemic to Queensland. The tree has great significance and history for the indigenous people of the land as a food source and cultural anchor. |
| ID Characteristic | Araucaria bidwillii is a tall emergent evergreen conifer with a distinct dome shaped crown, once mature. The lower part of the tree often has whorls of branches that give it a distinct two- tiered appearance. The female cones are large, 5-10 kilograms, green looking pineapples with edible nuts. Lanceolate leaves that are a glossy green and end in a sharp point, dark green in full sun and light green in low-light conditions. |
| Shape | The young tree is pyramidal in shape. As the tree matures the lower branches are lost and the crown of the tree becomes a distinctive, symmetrical dome shape. This crown is made up of dense tufts of branchlets and foliage massing at the end of the branches. With the loss of the lower branches, dormant buds grow creating shorter whorls of branches lower down the tree. |
| Landscape | The Bunya Pine is widely used as an ornamental. The location of the tree needs to be considered carefully, due to the height and spread that can be achieved over its lifespan. The other issue to consider is the large female cones that are produced. As the cones can weigh up to 10 kilograms, damage to property and public safety should be seriously assessed before planting. Some public gardens fence off the area when the trees are producing cones and National Parks in Australia enlist the use of signage to warn of the danger created from falling cones. The tree would truly make an amazing specimen tree and could be used as a wind break on very large estates or acreage, unsuitable for small spaces. |
| Propagation | The Bunya Pine is notorious for its unpredictable germination. It has been observed that a planted seed can take anywhere from one month to eighteen to germinate. Following this a tuber is formed and it is this tuber that can lie dormant awaiting optimal growing conditions before roots and a stem develop. The long-term success of such a large tree is reliant on establishing a strong and healthy ‘radical’ root that will be the anchorage and support for a life span that can be up to 600 years. |
| Cultivation | Araucaria bidwillii prefers full sun but also tolerates shade. Even though the plant requires regular watering it must be planted in well-drained soil that does not remain waterlogged. Naturally the tree grows on basaltic or other igneous substrates and occupies moist forest floors as well as drier grasslands. The Queensland climate is typically humid. Despite its tropical origins, the Bunya Pine has proven to be hardy enough to grow where frosts occur, and temperatures drop to around -4 Celsius. Sheltered exposure and a location that will allow the healthy development of the tap root to grow freely and extend deep into the ground are important. |
| Pests | Phytophthora multivora, a water mould that lives and is transported in soil and water. It attacks the roots, bark and cambium of the trees. |
| Notable Specimens | Caerhays Castle, Goran, Cornwall, United Kingdom. The best examples of Araucaria bidwillii can be seen in their natural habitat: Bunya Mountains National Park, Queensland, Australia has the world’s largest population. Blackall Ranges, Queensland. Upper Mary River Valley, Queensland. The upper regions of the Brisbane River, Southeast Queensland. Yarraman-Blackbutt area, Queensland. Cannabullen Falls, Northern Queensland. Mt Lewis, Northern Queensland, Australia. |
| Habitat | The tree has shown its adaptability, as it is noted to grow in subtropical rainforests, wet tropics, and colder climates further south in Australia. Genetic research has shown variation in the tree depending on its location. It is thought these genetic and morphological differences are a result of contrasting climates. It’s ability to accommodate varying precipitation is also noted. As witnessed in the wet tropics where rainfall of 1,500 – 2,000 mm and is evenly distributed through the year compared to the heavy summer rains of southeastern Queensland that are then dispersed with a dry season from April to September |
| Bark/Stem Description | The trunk of the tree is thick and sturdy with bark hard and rough, that is brown to black. Horizontal furrows on the thick bark can be quite deep on older trees, almost resembling the leg of an elephant. The juvenile trees have lighter coloured flaky bark in scales up to 2.5 x 7.5 centimeters. The branches are arranged around the trunk in regular whorls. |
| Flower/Leaf Bud Description | The leaf buds can be seen appearing singularly or numerously at the end of the branchlet. The buds are apical only. Each bud is light green and has an elongated conical shape, that ends in numerous pointed leaf tips in a somewhat floral arrangement. This corresponds with the radial/whorled leaf arrangement that is present on the branches. Each segment of the leaf bud is lanceolate and ends in sharp points. Size could not be determined from the literature. |
| Leaf Description | Juvenile leaves are hard and glossy-green, spirally arranged, showing in 2 rows ranging from 0.5 - 2 cm. Mature leaves grow to 2 - 3 cm and are overlapping, glossy, pungent, rigid and woody. |
| Flower Description | The male pollen cones are “narrow, cylindrical structures about 20 centimeters long on the ends of short branchlets that usually appear in autumn” (Louzeiro, 2020). These cones are covered in diamond shapes scales. Pollination occurs from September to October when the pollen grains are wind dispersed to the female cones. The female cones are remarkable, as large as 30 x 23 centimeters, upright, dark green and ovoid to spherical in shape, made up of numerous bracts with sharp tongues at the end. Each bract has a thin husk that covers the ovule. |
| Fruit Description | Female cones are pineapple-like and grow from 25 - 30 cm. Araucaria bidiwillii will take from 14 – 20 years to reach maturity before it will start to produce cones. The cones produce an abundance of seed during a mast crop, every three years. Each cone contains between 50 to 100 seeds and matures in the summer through to early autumn. The cones shed their seeds once they have fallen off the tree and ripened. Each seed is covered by a thin husk, beneath this the seed is housed in a shell that must be cracked open to reveal the seed. The seeds are approx. 5 x 3 centimeters, obovate and wingless. The cones resemble a large dark green pineapple, can weigh as much as 10 kilograms and measure 20 x 30 centimeters, ripening to become woody and brown in colour. |
| Colour Description | Leaves produced in the shade are observed to be glossy and light green while those exposed to full sun are a glossy dark green. The male and female cones are a dark green, turning brown as they mature. The tree is an evergreen with dark brown to black bark. |
| Texture Description | Course textured. |
Photographs
Araucaria bidwillii, form. Caerhays Castle, Goran, Cornwall, United Kingdom.
Araucaria bidwillii, leaf. Caerhays Castle, Goran, Cornwall, United Kingdom.
