Black Wattle

Common Name(s): Black Wattle

Scientific Name: Acacia mearnsii

Distribution: Native to Australia; introduced to many regions worldwide

Tree Size: 20-65 ft (6-20 m) tall, 1-1.6 ft (.3-.5 m) trunk diameter

Average Dried Weight: 46 lbs/ft³ (730 kg/m³)

Specific Gravity (Basic, 12% MC): .59, .73

Janka Hardness: 1,710 lb_f (7,590 N)

Modulus of Rupture: 17,660 lb_f/in² (121.8 MPa)

Elastic Modulus: 2,117,000 lb_f/in² (14.60 GPa)

Crushing Strength: 8,960 lb_f/in² (61.8 MPa)

Shrinkage: Radial: 3.1%, Tangential: 7.0%, Volumetric: 10.2%, T/R Ratio: 2.3

Color/Appearance: Heartwood is pink to light brown. Slightly lighter sapwood isn’t always sharply demarcated from heartwood.

Grain/Texture: Grain is interlocked, with a uniform medium texture and decent natural luster.

Rot Resistance: Rated as non-durable; poor insect resistance.

Workability: No data available.

Odor: No characteristic odor.

Allergies/Toxicity: Besides the standard health risks associated with any type of wood dust, no further health reactions have been associated with Black Wattle. See the articles Wood Allergies and Toxicity and Wood Dust Safety for more information.

Pricing/Availability: No data available.

Sustainability: This wood species is not listed in the CITES Appendices or on the IUCN Red List of Threatened Species.

Common Uses: Flooring, and tannins (harvested from bark).

Comments: Black Wattle has been introduced to many different parts of the world beside its native Australia. It was initially used in the production of tannins, (its bark can contain up to 40-50% tannin), but the species has subsequently been labeled an invasive species in many locales, displacing native vegetation.