Purple Mulga is an extremely rare and very dense timber type and is included on the CSIRO endangered species list. Mulga woodlands cover 20% of the Australian continent. The most common is Acacia aueura - the Mulga, which takes on several forms. One is the round form found in sandhill country, another is the Christmas Tree form, another the weeping tree form, and another like an umbrella inside out. In favourable conditions young plants will grow at a rate of 1 metre every 10 years up to a height of 10 metres. Reduced rainfall or drought conditions will slow down this process or bring it to a temporary halt, a mature tree will usually be more than 100 years old.