black acacia USDA PLANTS Symbol: ACME
U.S. Nativity: Exotic
Habit: Hardwood Trees
Acacia melanoxylon R. Br. ex Ait. f.

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Taxonomic Rank: Magnoliopsida: Fabales: Fabaceae (Leguminosae)
Synonym(s): blackwood, Australian blackwood, blackwood, blackwood acacia
Native Range: Australasia (GRIN); Tasmania, South Australia (BAIL);

Appearance
Acacia melanoxylon is a straight trunked, medium sized tree of the legume family (Fabaceae) with a dense crown. It is a thornless, evergreen tree 26-49 ft. (8-15 m) high. It can occasionally get up to 148 ft. (45 m) tall. Native of rainforest areas in southeastern Australia, it was introduced as a forestry planting to Hawaii, New Zealand, and South Africa. It was introduced to Hawaii as a forestry planting (Nelson and Schubert 1976).
Foliage
The leaves are bipinnate on seedlings. In mature trees coppice shoots usually become phyllodes. Phyllodes on Acacia melanoxylon are about 3-4 in. (7-10 cm) long. Foliage starts out greyish turning dark dull-green as it matures. The leaves are straight to slightly curved, with 3-7 prominent longitudinal veins and fine net-veins between.
Flowers
The pale yellow to whitish colored flowers have a powder puff appearance due to the presence of numerous stamens. Each one ranges from 0.2-0.4 in. (5-10 mm) in diameter. The flower clusters are borne on peduncles from 0.2-0.6 in. (5-14 mm) long. They are alternately arranged and arise from the phyllode axil. Flowering can occur year round.
Fruit
The fruit of Acacia melanoxylon is an elongated, flattened pod approximately 1.6-6 in. (4-15 cm) long and 0.1-0.3 in. (3.5-8 mm) wide. The pods are strongly curved, twisted or coiled. These pods are mostly glabrous with only a slight constriction between each seed. The pods are green and leathery when young, maturing to brown to reddish-brown in color and become woodier. The seeds are elliptic and about 0.1-0.2 in. (3-5 mm) long and 0.07-0.1 in. (1.7-3 mm) wide. Seeds are glossy, black and are encircled by a large pink to dark red aril.
Ecological Threat
Acacia melanoxylon is native to eastern Australia. This tree grows fast and tall, up to 148 ft. (45 m) tall. It tolerates a wide range of conditions and soils but grows better in colder climates. It invades areas such as natural vegetation, commercial timber plantations and farmland.

Selected Images from Invasive.orgView All Images at Invasive.org


Plant(s); Small tree
Forest and Kim Starr, Starr Environmental, Bugwood.org
Additional Resolutions & Image Usage

Tree(s); Small tree
Forest and Kim Starr, Starr Environmental, Bugwood.org
Additional Resolutions & Image Usage

Tree(s); Small tree
Forest and Kim Starr, Starr Environmental, Bugwood.org
Additional Resolutions & Image Usage

Tree(s); Small trees
Forest and Kim Starr, Starr Environmental, Bugwood.org
Additional Resolutions & Image Usage

EDDMapS Distribution:
This map is incomplete and is based only on current site and county level reports made by experts and records obtained from USDA Plants Database. For more information, visit www.eddmaps.org
 


State(s) Where Reported invasive.
Based on state level agency and organization lists of invasive plants from WeedUS database.

U.S. National Parks where reported invasive:
Haleakala National Park (Hawaii)



Invasive Listing Sources:
California Invasive Plant Council
Faith Campbell, 1998
Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
John Randall, The Nature Conservancy, Survey of TNC Preserves, 1995.
Reichard, Sarah. 1994.  Assessing the potential of invasiveness in woody plants introduced in North America. University of Washington Ph.D. dissertation.
University of Hawaii, Botany Department, Hawaiian Alien Plant Studies, 1998