Araucaria bidwillii

Did You Know?

• The species was described by English botanist William Jackson Hooker in 1843, based on material collected by John Carne Bidwill.
• Sulphur-crested cockatoos, short-eared possums, fawn-footed melomys, and wallabies eat the seeds, with cockatoos acting as dispersal agents.
• The genus name Araucaria derives from the Spanish word Araucanía, the name of an area in Chile where the first species originated.

Description

Araucaria bidwillii grows to a height of 50 m with a single unbranched trunk up to 1.5 m in diameter, covered in dark brown or black flaky bark. Branches are arranged in whorls at regular intervals, held horizontally, with upper branches somewhat ascending and lower ones slightly drooping, creating a distinctive egg-shaped silhouette. The leaves are small, rigid, and sharply tipped, narrowly triangular and sessile, up to 5 cm long and 1 cm wide, with fine longitudinal venation, glossy green above and paler underneath. They are arranged in a pattern that is both distichous and decussate, meaning opposite pairs are rotated 90° along the twig. Male pollen cones are spikes up to 20 cm long, maturing around October to November. Female seed cones are much larger, reaching up to 30 cm long and 20 cm wide, roughly the size of a rugby ball, and weigh up to 10 kg. At maturity from December to March, they are green with 50–100 pointed segments, each enclosing a seed. The edible seeds, called bunya nuts, are ovoid to long-elliptic, measuring 2.5 to 5 cm long. The tree changes its architectural growth model over time, initially following Massart's model and gradually shifting to Rauh's model.

Cultural significance

Each family owned a group of trees, passed down through generations, said to be the only case of hereditary personal property among Aboriginal people. Large festival harvests occurred every two to seven years after cones fell, drawing people from hundreds of kilometres to the Bunya Mountains. Messengers invited diverse tribes, up to thousands, from as far as Charleville, Bundaberg, Dubbo, and Grafton, who stayed for months to feast, settle disputes, arrange marriages, and trade goods. These gatherings were considered Australia's largest Indigenous event, an armistice accompanied by trade and discussions on regional issues. Due to the tree's sacred status, some tribes would not camp among bunyas, and in some regions the tree was never cut. Representatives from many groups across southern Queensland and northern New South Wales met to discuss environment, social relationships, politics, and Dreaming lore, settling conflicts and addressing breaches of laws.

Uses

Indigenous Australians eat bunya nuts both raw and cooked, including in immature form. Traditionally, nuts were ground into a paste, eaten directly or cooked in hot coals to make bread called manu. They were also stored in creek mud and eaten fermented, considered a delicacy. Bunya shoots were consumed, and the bark used as kindling. Today, bunya nuts are sold in grocery and street-side stalls in rural southern Queensland, and some farmers experiment with commercial cultivation for nuts and timber. The nut is popular as a bushfood, used in recipes from pancakes and breads to casseroles, pesto, and hoummus. Boiling the nuts yields a red, flavoursome tea. Nutritionally, the nut contains 40% water, 40% complex carbohydrates, 9% protein, 2% fat, 0.2% potassium, and 0.06% magnesium, and is gluten-free. Bunya timber is valued as tonewood for stringed instruments, used by Australian companies Maton and Cole Clark for guitar soundboards, and by cabinet makers for over a century.

Cultivation

Bunya nuts are slow to germinate; a set of 12 seeds in Melbourne took an average of six months, with first emergence at three months, and roots developed after one year. First leaves form a dark brown rosette, turning green only after the first stem branch appears. Young leaves are soft but become hard and sharp with age. Cuttings from erect shoots can succeed, but side shoot cuttings will not grow upright. A germination test of 100 seeds from a cultivated tree at Petrie, north of Brisbane, planted in early February 1999 in sterile potting mix and watered weekly, resulted in 87 germinating over three years: 55 emerged from April to December 1999, 32 from January to September 2000, one in January 2001, and the last in February 2001. They reach 35 to 40 m in height and live about 500 years.