Acacias, or Wattles, grow all over Australia – there are over 1000 known species.
The Golden Wattle, Acacia pycnantha, is the Australian national floral emblem and our national colours, green and gold, come from the flowers and leaves of this popular tree.
They have very small flowers that occur in clusters to make their characteristic bright yellow display. Some have paler coloured flowers and one species, Acacia purpureapetala, has purple flowers. Most species begin to flower in late winter but the huge variety means there is usually a wattle flowering at any time of the year.
After a bushfire, acacias are often the first plants to recover and revegetate the area. Ants tend to store acacia seeds underground which may help to explain why the seeds germinate so quickly following a fire – they are already in the soil waiting for the right conditions.
Wattles have a strong smell which attracts birds, bees, wasps and beetles. They are a great habitat for small birds, providing shelter, perching and nesting sites, and attracting insects for them to eat. Different species attract different birds and those that love wattles include crested pigeons, rufous whistlers, grey shrike-thrushes, white winged trillers, thornbills, silvereyes, wrens and singing honey eaters.
Many acacias produce "galls"; lumps or malformations that occur as a result of insects, viruses, worms, bacteria or physical damage, When caused by an insect laying eggs, they attract galahs and rosellas who will tear it open to eat the insects.
Dense growths of acacias give sugar gliders and squirrel gliders a place to live and they also feed on the insects that are attracted to the flowers. The Leadbeaters possum feeds on the gum of Silver Wattle and Hickory Wattle.
Wattle seeds are eaten by parrots and pigeons and Black Cockatoos and Gang Gangs tear open the bark to search for grubs in the wood of older wattle trees.
Wattle seeds are well known bush foods and a traditional food source for aboriginal communities. Not all acacia varieties have edible seeds so if you want to have a go at making wattle damper or wattle seed cake, its best to buy the seeds from a supplier.
Did you know?
Acacias are actually legumes - they can acquire nitrogen directly from the atmosphere with the aid of soil bacteria (Rhizobium sp) through nodules on the roots of the plant.
Ants and acacias have a close relationship. The seeds are coated in an oily fleshy outgrowth called an aril. Ants take the whole seed back to their nests where they eat only the aril and the seed remains safely stored underground ready for germination.
Sheoaks are very unusual plants because they have separate male and female plants. Each year the males will turn a dusky red colour as they release their pollen. The female trees have small red flowers and lots of seed cones. The sheoak doesn’t have big leaves, instead they have branchlets ..