Brachychiton populneus aka Kurrajong

Brachychiton populneus, or kurrajong, is a tree in the mallow family. Its native range runs from southeast Queensland to eastern Victoria. It grows in coastal areas and farther inland. Its habitats include dry woods and rocky slopes. It grows on many soils, but often favours limestone. Gardeners also grow it as an ornamental tree.

The tree grows fast and forms a dense crown. Its outline can be oval, rounded, or broadly spreading. Garden references give heights of 49–59 feet [15–18 metres]. Broader accounts report heights up to 66 feet [20 metres]. The crown can spread to 59 feet [18 metres]. Trees in open sites form a short, stout trunk. This can reach 1.6–3.3 feet [0.5–1 metre] across. The tree keeps its leaves year-round or loses some seasonally. Its inner bark yields fibre for cord, nets, and bags.

PFAF gives the flowering season as May to July. It lists pink and red flower colours. Each flower is either male or female. Both sexes occur on the same tree. The fruit forms a capsule that opens to expose seeds. Fine hairs inside the capsule can irritate skin. Wear gloves when handling the capsules, as Useful Tropical Plants advises.

Give this tree full sun and soil that drains well. It prefers soil with moderate fertility but accepts many soil types. These include sand, loam, and clay, across mildly acid to alkaline conditions. It tolerates dry soil and also grows in moist soil. Avoid wet ground, above all during winter. PFAF lists USDA zones 8–11, but reports of frost tolerance differ. Useful Tropical Plants warns that young trees suffer severe damage at −1°C. It reports that −5°C can kill mature trees. PFAF records survival at lower temperatures under some conditions. It still questions outdoor hardiness in Britain. PFAF lists it for specimen planting and notes pest tolerance.

Aboriginal Australians have used the seeds and young roots as food. Sources describe eating the seeds raw or roasted. Roasted seeds also serve as a coffee substitute. The seeds contain protein, fat, zinc, and magnesium. Roots from very young trees provide a yam-like food. PFAF records no known medicinal uses. Its statement of no known hazards needs caution: another source reports irritating capsule hairs.