Common Name: Grass tree, Balga
Family: XANTHORRHOEACEAE (3 subfamilies, 36 genera)
Subfamily XANTHORRHOEOIDEAE (1 genus)
Origin of Scientific Name
Xanthorrhoea –from Greek xanthos = yellow + rheo = to flow, referring to the gum that is exuded from the stem.
preissii – after J A Ludwig Preiss, a botanical collector born in Germany, who visited the Swan River colony, Western Australia, from December 1838 to January 1842 and collected many thousands of plant and animal specimens.
Xanthorrhoea preissii is a perennial tree-like monocot with a trunk comprised of a fibrous centre surrounded by a ring of leaf bases that are often blackened by fire.
The long, highly flammable leaves grow from the top of the trunk and as they die, their persistant leaf bases add to the height of the trunk.
The tall flowering spike grows to 1.5m to 2.5m long and is covered with thousands of small white or cream flowers, the nectar of which attracts pollinating birds, insects and mammals.
The very slow-growing Grass tree has a lifespan of 600 years with a growth rate of one to two cm per year, or more in areas frequently exposed to bush fires.
Refer to the distribution map for this species via the Department of Environment and Conservation's FloraBase online herbarium.
June to December.
Easily propagated from fresh seed sown in autumn or winter, after treatment with smoke or smoke water. They normally germinate in two to three months, but may take up to a year without smoke treatment.
They are tolerant of most situations once established, but prefer full sun to partial shade and must have a well-drained soil as they are susceptible to root rot.
Pests and Diseases
Read the Department of Agriculture and Food’s fact sheets about common pests and diseases that affect Xanthorrhoea preissii here.
Considered a most useful plant for local aboriginal people, its leaves were used for thatching and bedding, flowers were sucked for sweet nectar, yellow gum from the spike was chewed and lengths of spike used to drill for fire lighting. Red, inedible gum oozing from the trunk made a fibreglass-like glue for tool making.
View in Kings Park
View these unique Western Australian natives growing naturally throughout Kings Park bushland, planted throughout the Botanic Gardens and precincts, and in front of and around Aspects of Kings Park and Fraser’s Restaurant. There are 17 grass trees planted at the Bali Memorial site - one to represent each of the Western Australian lives lost in the tragic events of 2002 and 2005. To help locate these sites, you may wish to download the Western Australian Botanic Garden Guide brochure via our brochures page.