12 July 2024
Water Conservation Series – Drought Resistant Plants
Fascinating facts - The Mulga
Have you heard of the Mulga? This remarkable plant is one of nearly 1,000 Acacia species found in Australia. Known as Acacia aneura, the Mulga can either be a shrub or small tree. The name “Mulga” is derived from an Aboriginal word meaning long, narrow shield made from Acacia wood.
Acacias are native to both Africa and Australia, with Acacias being Australia’s largest genus of flowering plants. In this article we will explore the fascinating facts about the Mulga, including its growing conditions, locations in Australia, benefits, and why it is considered drought resistant.
Characteristics
The Mulga can grow to a height of 10 metres, but in areas with low rainfall or very shallow soils, it typically reaches around 3 metres. It is found in arid outback regions of Australia, excluding Victoria. While Acacias are generally known as short-lived trees, the Mulga can live to a hundred or more. With a growth rate of 1 meter per decade, some trees have been discovered with over 100 years of growth rings.
The Mulga is characterised by narrow phyllodes (leaves), most of which are less than 3mm wide, bright yellow flowers and conspicuous bunches of green seed pods. It is endemic to sandy soils and dunes in arid climates.
Drought Tolerant Properties
The Mulga is highly drought tolerant for several reasons. Its narrow phyllodes reflect heat, minimising evaporation. The sophisticated arrangement of its phyllodes and branches channels rainwater to the stem, which then directs it to the ground reaching its taproot. Seedlings as small as 10 cm tall have been found to have taproots reaching 3 metres deep. During dry periods, it loses its leaves which act as mulch, not only benefiting itself and creating an ecosystem.
Uses
The Anangu people roast and grind Mulga seeds into an edible paste like peanut butter and consume the tree’s gum. The roots host witchetty grubs, another source of bush food. A sweet exudation produced by the plant after a sap sucking insect attack was eaten directly or dissolved in water to make a sweet drink. Early settlers who referred to this as “bush lollies.”
A white, powdery substance on the leaflets and small branches was used as resin for joining tool parts and repairing cracks or holes in wooden bowls. The timber, which turns dark red -brown when polished has been used to make tools and boomerangs.
Livestock graze on the leaves within reach and recent leaf fall. During droughts, farmers may use Mulga as a food source, though it is not recommended for animals already affected by drought because of its low nutritional levels. To address nutritional deficiencies, supplementing with loose licks is recommended. A Slick Feeder is an ideal container to facilitate the distribution of loose lick rations.
The Mulga, a resilient member of the Acacia family, displays the adaptability of Australia’s native flora. Its drought tolerance and varied uses highlight its importance. The Mulga is vital to Australian ecosystems and culture. Appreciating drought resistant plants offers insights into sustainable practices and the need to conserve our natural heritage.
