pronounced:brak-ee-KY-ton pop-ULL-nee-uss
This tree is sometimes placed in Sterculiaceae.
Brachychiton is from the Greek βραχυς (brachus), short and χιτων (chiton), a tunic. This is an allusion to the bristles surrounding the seed in the fruit. Populneus is from the Latin populus, the poplar tree – ‘like poplar’. The specific name for the Kurrajong is often misspelt populneum, no doubt in the belief that a neuter form of the Latin is needed to go with Brachychiton; but the Greek ‘–on’ ending in this case is masculine, and so requires the masculine form of the adjective. Kurrajong is an Aboriginal name for the tree.
The species Brachychiton populneus has two subspecies that differ in adult leaf shape. Ssp. trilobus has a more northerly and inland distribution, and has leaves with 3 and sometimes 5 narrow lobes, while the adult leaves of ssp. populneus have reduced side lobes and appear more like those of poplars. There are two specimens of the latter subspecies in Barbarra Street, Picnic Bay.
The Kurrajong is naturally distributed from north-eastern Victoria to Townsville, and from the coast through to the semi-arid inland. It is a relatively tall tree, growing up to about 20 m high, with a thick, smooth, grey-barked trunk. It produces a light and soft timber that has been used for lattices, and as a softwood for interior furnishings.
Flowers are bell-shaped and whitish in colour, with the inner flower tube streaked purple-brown. They are borne in clusters near the ends of the branches. Cultivated hybrids involving Brachychiton populneus display pink or red flowers. Seeds are borne within woody boat-shaped fruit up to about 10 cm long, and are surrounded by fine hairs that can cause skin and eye irritation.
Juvenile plants, which display attractive lobed leaves and swollen taproots, make good pot plants, tolerant of dry and pot-bound conditions, and responding well to pruning.
Trees are typically stout with glossy-green foliage, and are widely used as street trees both in Australia and overseas. Native populations on agricultural land are often retained to provide dense shade and drought fodder – leaves lopped from the branches are nutritious, and liked by stock, but eating the fruits may cause illness. The deep-rooting trees have minimal impact on cropping, and also support honey production. Once a tree has been lopped for forage, it usually takes 3 to 5 years before it recovers sufficiently to be lopped again.
With the aboriginal peoples, the roots of young Kurrajongs were a popular food, and the seeds were probably also eaten, after processing to get rid of the hairs. Twine could be made from the bark of the trees, and, certainly in the Hastings River region at least, fishing nets were made. These were placed across creeks and streams, and the fish driven into them. Nets were also tied between trees on the river banks, and waterfowl were driven into them by boomerangs thrown above the birds to simulate birds of prey. Early European settlers roasted and ground the seeds of the Kurrajong to make a coffee-like beverage.
The tree is easily propagated from seed, or from self-sown seedlings that come up under trees where stock have congregated and disturbed the ground.
Quite a few Lepidoptera larvae use this tree as a food source, including:
• the Hairy Leaf-eating Caterpillar Xanthodes congenita,
• the Pencilled Blue Candalides absimilis,
• the Eastern Bronze Flat Netrocoryne repanda,
• the moth Chasmina pulchra, and
• the Kurrajong Bag Moth Dichocrosis clytusalis.