Australian Native Grass Tree- Xanthorrhoea Preissii or Balga

Australian Native Grass Tree- Xanthorrhoea Preissii or Balga

Australian Native Grass Tree- Xanthorrhoea Preissii or Balga

The Grass Tree or Xanthorrhoea ‘yellow flow’ is named due to the plant’s yellow-coloured sap. It can be found in most sand-rock composite soil all around Australia and is one of our oldest and slowest-growing native plants still in existence. It has a natural life span of around 350-400 years, but some species have even been estimated to live up to 600 years old.


Grass Tress are not typically “trees” but are monocots. This means they have a central embryonic leaf from which the main plant grows. As the plant ages, the leaves die and become stuck together by the plant’s sap giving it a trunk-like appearance. Grass Trees also produce a thick spear-like flower multiple times a year to attract native wildlife and insects.

Perhaps, the most iconic Grass Tree is the Xanthorrhoea preissii, or Balga as named by the Mooro Nyoongar of Western Australia’s Southwestern region. The preissii is known for its fibrous leaves and black trunk. When exposed to fire, these leaves burn up to insulate the body of the tree protecting it from harm and resulting in a blackened appearance. Most Grass Trees will thrive after a bushfire or controlled burning as it promotes new growth.

Grass Trees are commonly known as ‘Black Boys’ due to the black trunk and arrow-like flower somewhat resembling a young indigenous boy holding a spear. Although still used, Grass Trees or Balga are the respected and preferred names.

Although Grass Trees are becoming increasingly popular as domestic feature trees, they are heavily regulated. Due to mass land clearing for cattle grazing and farming, in combination with their extremely slow growth rate (around 2cm a year) Grass Trees are unfortunately becoming endangered. Some species such as the Xanthorrhoea arenaria and Xanthorrhoea bracteata are even protected under the Australian Biodiversity Conservation Act of 1999 and classified as ‘vulnerable to extinction’.

By preserving these magnificent prehistoric natives in their natural habitat, we can ensure their continual survival for hundreds of years to come and along with it, the wildlife that regard the Grass Tree as their home. 

Keen to read more? Check our blog here on the Buxus Ball.