blackwood (Acacia melanoxylon)

Size: 
5–30 m high, depending on rainfall and soil.
Form: 
Tree
Natural Distribution: 
Wet and dry forests in eastern States and South Australia.
Description: 

Blackwood is Australia's tallest Acacia, with its height varying from 5 to 30 metres, depending on where it is growing. In rainforests it can grow to 30 metres tall.  It lives much longer than other acacia species.

Blackwood form changes dramatically, depending on where it is growing - in rainforests and swampy areas it grows tall and straight; in arid coastal sites it is often short and spreading.

Tasmanian Aboriginal people used its timber for waddies and digging sticks (for digging up roots and tubers). They soaked the bark in water for an infusion to treat arthritic joint pain. They also found food value in blackwood gum soaked in water, and probably ate its seeds. Blossom from this and other acacia trees, hung near where they slept, was thought to induce sleep. 

These days blackwood is a prized timber, known worldwide as one of the best furniture and craft timbers.

Like other acacias, Acacia melanoxylon is an effective fixer of the essential element nitrogen, thereby making it available to other plants.

Blackwood seeds can survive for hundreds of years in the soil until fire or other disturbance breaks their tough outer casing.

Habitat value

The seeds are a source of food for birds such as grey currawongs and green rosellas. Brown thornbills also forage amongst twigs, leaves and branches of the blackwood. 

(Photos:  David Fitzgerald)

STUDENT INQUIRY QUESTIONS

Do you have any furniture at home - or at school - made from blackwood timber? 

Find the tallest blackwood in the school's bushland and estimate its height.