Monday, December 19, 2005

Belonging to the Sterculiaceae family, Brachychitons are found in Australia and Papua-New Guinea with some 30 species being endemic to Australia. B. acerifolius, B. australis, B. bidwillii, B. discolor, B. populneus ssp trilobus, B. rupestris and a naturally occurring hybrid B. x turgidulus are known to occur in the Port Curtis pastoral area.

Commonly known as kurrajongs (from an aboriginal word meaning ‘fibre-yielding plant'),
Brachychitons derive their scientific name from the Greek words brachys (short) and chiton (a coat of mail or tunic). This is a reference to the short, massed hairs around the seeds inside the fruits.

Usually trees, Brachychitons sometimes have swollen trunks e.g. B. rupestris, and are often deciduous while flowering. The leaves are alternate, simple, often large, entire or lobed, often different when juvenile and sometimes different on the same tree. Unisexual, 5 (rarely 6)-lobed, bell-shaped flowers form in axillary clusters.

Petals though absent are replaced by the petaloid lobes of the calyces. Fruiting follicles are tough and hard and split down one side to reveal numerous seeds in 2 rows separated into honeycomb-like compartments. The seeds are released gradually.

Both Aborigines and Europeans have made good use of various Brachychiton species. Aboriginal uses have included - eating young shoots, the zinc and magnesium rich seeds raw or roasted (minus the hairs), the roots of young plants raw or cooked and the gum exudate from trunk wounds; preparing an eye-wash from the inner bark of a Northern Territory species; obtaining water from the roots and making ropes, fishing nets and dilly bags from inner bark fibres.

European uses include - eating the seeds raw or roasted and chewing the mucilaginous pulp of B. rupestris for its starch; using the seeds of B. populneus as a coffee substitute (first tried by Ludwig Leichhardt); using Brachychiton foliage and the trunk pulp of B. rupestris as a drought fodder for stock (in the latter case deaths sometimes occurred from nitrate poisoning while B. populneus seeds were reportedly toxic); using the soft timber of B. acerifolius for ply and model-making and as a balsa substitute and B. populneus timber for lattice construction and interior furnishings; formerly using gum exudate to hold in dental plates; planting species such as B. acerifolius, B. populneus and B. australis as ornamentals and street trees.

Brachychiton leaves, seeds, flowers and nectar provide sustenance for many native animals. Records indicate that at least I species of possum, 24 bird species, 7 butterfly species, 5 moth species and other insect species use Brachychitons as a food source.
Joel Plumb

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