Common Name:
bottle tree, kurrajong
Family Name:
Malvaceae
Botanical Name:
Brachychiton populneus
Sub Species:
Variety:
Forma:
Cultivar:
Characteristics:
Kurrajong is a striking broadleaved evergreen tree native to southeastern Australia. Mature trees can reach 10-20 meters (30-60 ft) in height and 5-10 meters (15-30 ft) wide. It is relatively drought-tolerant fast-growing. The canopy is dense, and spreading becoming wider and more pyramidal in shape wth age. It has a single trunk, which is characterized by its distinctive bottle-shape tapering downwards and widening at the base. The bark is initially green, but becomes more grey and more cylindrical with age. Leaves are simple, alternate, glossy green, 5-10 cm (2-4 in) long and usually ovate- lanceolate (resembling poplar leaves), occasionally with 3-5 lobes. Flowers are small, bell-shaped and white-cream in color with pink-red speckles on the inner corolla tube and are organized into clusters of ~5 flowers. Fruit is a 1-7cm (1/4 – 2 in) long, boat-shaped, woody capsule, turns dark brown-black as it matures. The fruit contains numerous round, yellow seeds which are covered in hairs that can be irritants to human skin. The tree also has deep roots which support its adaptation to drought, but can also conflict with underground plumbing in built environments.
Compound:
Bra pop
Geographic Origin:
Australia
Ecozone Origin:
Australasia
Biome Origin:
Natural History:
The bottle tree is native to and is distributed across eastern Australia (3,4).
Cultivation Notes:
Propagation of B. can be done from seed or cutting (4). Germination success increases when seeds are immersed in hot water and allowed to soak for 12 hours in the cooled water (4). Grafting is also sometimes done to propagate desirable characteristics (4), such as a leaf shape, which tends to vary in this species. When transplanting seedlings from containers, protect the taproot (4). Plant in full - part sun (1,3). The bottle tree is tolerant of drought and poor soil conditions, but responds well to soil with good drainage and grows better with deep watering every 1-2 weeks in the hottest summer months (3,4). In some climates, the bottle tree is susceptible to many pests and diseases (4) however, in the low desert of Southern Arizona it is resistant to most disease except for Texas root rot, to which it is highly susceptible (5).
Ethnobotany:
Australian aborigines used the bottle tree as a source of fiber from which to make twine for bandages(2), nets, and dilly bags(1) and it is still cultivated for the use of its fiber(4). The gum exudate can be eaten, the taproot can be eaten and is described as “carrot-like”(4) or “yam-like”(1), and the seeds can be ground up and used as a coffee substitute(4). The raw or roasted seeds have been eaten by aboriginal people and are high in protein, zinc, and magnesium(1). Currently, the bottle tree is commercially cultivated and is commonly used as a street tree in Australia and other countries(4).
Height:
20 - 50 feet
Width:
20 - 50 feet
Growth Rate:
Slow Growing
Grow Season:
Spring
Flower Season:
ForeSummer
Color:
White
Function:
Shade
Spread:
Non-spreading
Allergen:
Non-allergenic
Invasive:
Benign
Toxicity:
Benign
Hardy:
Hardy
Water Use:
Moderate Water Use
