drooping sheoak (Allocasuarina verticillata)
This modest tree, found everywhere along Tasmanian coastline and in drier parts of the interior, comes in male and female forms. Male trees have long tendrils of rust-brown flowers, while female trees have tiny red flowers, which later develop into oblong cones.
The long, needle-like leaves of sheoaks are actually its stems. Its leaves are reduced to rings of tiny scales at intervals along its stems, making this plant extremely drought resistant.
Aboriginal people used the timber to make waddies and spears. In its sap, its green seed-pods and its young leaves, they found both a food and a thirst-quencher. Toothache and other pains were relieved by a gargle made from its sapwood and bark. And its wood, especially when immersed in water, attracted protein-rich grubs.
Sheoak timber produces a very hot fire. Early settlers used its ash to whiten sheets and to make soap, and found that honeybees liked its pollen. Today it is valued mainly for its beautifully grained red timber.
Sheoak’s ability to develop extensive root systems in poor coastal soils, including sand dunes, makes it a valuable soil-stabiliser. Its fallen foliage supresses weeds.
'Casuarina' comes from the Malay word 'kasuari' - its foliage resembles the plumage on a cassowary bird.
Fungi on its roots are eaten by bandicoots, potoroos and bettongs. Seed-eating birds such as yellow-tailed black cockatoos and green rosella feed on the cones. Brown and striated thornbills, and superb fair-wrens forage for tiny invertebrates in the foliage. The flowers' pollen attracts honeybees and butterflies.
(Photos: Richard Barnes, David Fitzgerald, Bronwyn Barton)
STUDENT INQUIRY QUESTIONS
Find a sheoak. Is it male or female? How can you tell?
Can you see the tiny leaves around the needle-thin stems? Why do you think the leaves have evolved to be this tiny?
Find some seeds inside a cone. Can you see the tiny wing on each seed? What is the purpose of the wing?
Find seeds belonging to other plants and compare them.