Assets with Eyes

Flowers of sunshine

29 Jul 2020

Acacias, commonly known as wattles, are some of the most iconic and easily recognisable Australian plants. In fact, the Australian Golden Wattle (Acacia pycnantha) is our national flora emblem. There are many acacia species at Sydney Olympic Park, 14 in the critically endangered Sydney Turpentine Ironbark Forest community located within Newington Nature Reserve, and several more planted across the Park. Many of them are putting on a winter flower show right now.

Of the 1,350 acacia species found across the world, almost 1,000 are found in Australia, ranging from groundcovers to shrubs and trees. They are fast-growing, short-lived pioneer plants, establishing quickly after fires and soil disturbance, and tolerant of a broad range of conditions, from coastal to inland to alpine regions.

The majority of acacias have developed an interesting adaptation in response to Australia’s hot, dry climate; their leaves may look like leaves at first glance, but they are actually flattened leaf-stalks called phyllodes that have been modified to look and function like leaves. Phyllodes make acacias more drought-tolerant as they are tough, leathery and resistant to water loss.

Acacias flower throughout the year. The flowers, arranged in globular heads or cylindrical spikes, vary from pale cream, vibrant yellow to gold, and are a highlight particularly in winter. At this moment, Sickle-leaved Wattle (Acacia falcata), Prickly Moses (A. ulicifolia) and Fringed Wattle (A. fimbriata) are flowering, soon to be followed by Sydney Green Wattle (A. decurrens), Sally Wattle (A. floribunda), Myrtle Wattle (A. myrtifolia), Coast Myall (A. binervia), Straight Wattle (A. stricta) and Sydney Golden Wattle (A. longifolia). Acacias in full bloom are best experienced around the Brickpit horsetrail, along the Waterbird Refuge in Badu Mangroves, and in Narawang Wetland. However, you’ll find acacias right across the Park, even in the Town Centre.

Apart from the show put on by the sweetly perfumed flowers, acacias also provide shelter and food for native wildlife. Ants harvest the fallen seeds, and insect pollinator such as beetles, wasps and native bees feast on the protein-rich pollen, in turn attracting birds that prey on small insects. Yellow-tailed Black Cockatoos search for acacias infested with wood-boring moth or beetle larvae, using their strong beaks to excavate into wood to locate the grubs for a juicy meal. Acacias also provide a host of valuable resources for Indigenous peoples. The seeds from some species can be ground into flour and cooked like a damper; extracts from bark, leaves and phyllodes are used for medicinal purposes; wood from various species are used to make spear, clubs, boomerangs and shields; and leaves may be used to stun fish in waterholes to make them easier to catch. Later, early Europeans used the young and flexible branches to make interwoven timber panels called wattle for building (hence the common name), and used the tannin-rich bark of some species as tea substitute, and for tanning animal hide to make leather.

Next time you’re in the Park, have a closer look at the acacias, and see how many types you can find!

An acacia in full bloom on Olympic Boulevard
The bright yellow globular flowers of Sydney Green Wattle
The delicate pale yellow blooms of the Fringed Wattle

 An acacia in full bloom on Olympic Boulevard

 The bright yellow globular flowers of Sydney Green Wattle

 The delicate pale yellow blooms of the Fringed Wattle

 

           
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