Acacia pycnantha Benth., Fabaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  High risk, score: 16 (Go to the risk assessment)

Common name(s): [more details]

English: broadleaf wattle, golden wattle

French: acacia doré

Habit:  shrub/tree

Description:  "Shrub or tree usually 3-8 m high. Branchlets sometimes pruinose, glabrous. Phyllodes often pendulous, falcately recurved to oblanceolate, pulvinus 4-7 mm long, much-narrowed at base, normally 9-15 cm long and 10-35 mm wide, obtuse to acute, coriaceous, glabrous, with prominent midrib, penninerved; gland often slightly exserted, sometimes 2, with the lowermost 3-45 mm above pulvinus. Inflorescences racemose; raceme axes 2.5-9 cm long, stout, glabrous; peduncles 3-6 mm long, stout, glabrous; heads showy, globular to obloid, densely 40-80-flowered, bright golden, sometimes lemon yellow; bracteoles evident in buds; laminae subcircular, > 0.5 mm diam., dark brown to blackish, white-fimbriolate. Flowers 5-merous; sepals united. Pods linear, 5-13 cm long, 5-7 mm wide, firmly chartaceous to thinly coriaceous, glabrous. Seeds longitudinal, ±oblong, 5.5-6 mm long, somewhat shiny, black; aril clavate"  (Flora of Australia online).

Habitat/ecology:  In Australia (native), "grows in sand or loam, in Eucalyptus forest or woodland, open scrub and heath"  (Flora of Australia online).

Propagation:  Seed

Native range:  Australia (New South Wales, South Australia, Victoria); cultivated and naturalized elsewhere (GRIN).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Guam Guam Island	Guam Island	introduced	Raulerson, L. (2006) (p. 33)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia Australia (continental)	Australia (continental)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011) South Australia, Victoria
Australia Australia (continental)	New South Wales	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Indonesia Indonesia	Indonesia (Republic of)	introduced	ILDIS Co-ordinating Centre (2011)
New Zealand New Zealand	New Zealand (country)	introduced	ILDIS Co-ordinating Centre (2011)
United States (west coast) United States (west coast states)	USA (California)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2011)

Comments:  This species is invasive in South Africa.

Control: 

Biological:  "Biological control of invasive golden wattle trees (Acacia pycnantha) by a gall wasp, Trichilogaster sp. (Hymenoptera: Pteromalidae), in South Africa".

Additional information:
Fact sheet from World Wild Wattle.
Fact sheet from Florabank.
Information on biological control research from the Plant Protection Research Institute of South Africa.

Additional online information about Acacia pycnantha is available from the Hawaiian Ecosystems at Risk project (HEAR).

Information about Acacia pycnantha as a weed (worldwide references) may be available from the Global Compendium of Weeds (GCW).

Taxonomic information about Acacia pycnantha may be available from the Germplasm Resources Information Network (GRIN).

References:

Australian Biological Resources Study. 2011. Flora of Australia Online. Australian Biological Resources Study, Canberra.

ILDIS Co-ordinating Centre. 2011. International Legume Database & Information Service. Online searchable database.

Raulerson, L. 2006. Checklist of Plants of the Mariana Islands. University of Guam Herbarium Contribution 37:1-69. .

U.S. Dept. Agr., Agr. Res. Serv. 2011. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.

U.S. Dept. Agr., Nat. Res. Cons. Serv. 2011. The PLANTS Database. National Plant Data Center, Baton Rouge, LA 70874-4490 USA.