Acacia dealbata Link, Fabaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  High risk, score: 22 (Go to the risk assessment)

Common name(s): [more details]

Chinese: yin jing

English: Sydney black wattle, mimosa, silver wattle

French: acacia bernier, acacia blanc, mimosa argenté, mimosa de Bormes

Spanish: acacia francesa, aromo, aromo de castilla, aromo del pais

Habit:  shrub/tree

Description:  "Shrub to large tree; twigs ribbed, densely puberulent. Leaves 2-pinnate, alternate, densely puberulent on rachis and sparsely hairy on pinnules; pinnae in (6)-10-21 pairs; pinnules in 25-40-(50) pairs, fairly close set, glaucous, narrow-oblong, obtuse or subacute, entire, 2-4-(7) x c. 0.75 mm; petiole (5)-10-20 mm long; stipules inconspicuous; solitary glands present between each pair of pinnae, usually except basal pair. Inflorescence of numerous, many-flowered, medium yellow, globose heads arranged in axillary, compound racemes ± = leaves. Flowers 5-merous, sessile. Pod glabrous, ± straight, 50-100 x 8-12 mm; aril scarcely folded, thickened to one side of seed.  Leaves of seedlings usually differ markedly from those of mature trees in being less glaucous, having fewer pinnae and fewer and larger pinnules. However, the distribution of glands and stem hairiness is the same as that of mature trees. Some flowering specimens have leaf forms similar to those of seedlings; again stem hairs and gland distribution distinguish these specimens"  (Webb et al., 1988; 705).

Description from Flora of Australia online.
Description from Flora of China online.

Habitat/ecology:  "Where native, this plant grows as a tall tree in mountain forests and along watercourses and in dry sclerophyll forests, remaining shrubby under dry conditions.  It forms dense thickets that suppress native vegetation, disrupt water flow and increase erosion along streambanks.  The plant is nitrogen-fixing and increases soil fertility"  (Weber, 2003; p. 14).

In New Zealand, "waste places, scrubland, riverbeds. In many areas silver wattle forms dense stands by suckering"  (Webb et al., 1988; 705).  "In Chile this species grows in the following environmental conditions:  Low altitude, interior valleys; coastal mountains, 500-2000 m; coastal areas, 0-500 m.  Somewhat dry areas where the drought may last 3-5 months, precipitations of 400-800 mm. are concentrated in winter; humid areas, with almost constant rainfall, short dry periods are possible (generally not longer than 1 month).  Fully exposed to the sun, level areas or slopes facing north; some shadow, some protection against direct sunlight, some shadow from vegetation, filtering about 20 - 40 % of light"  (Chileflora).

Propagation:  Seed

Native range:  Southeast Australia, Tasmania (Webb et al., 1988; 705).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia (Pacific offshore islands) Norfolk Islands	Norfolk Island	introduced invasive cultivated	Australian Biological Resources Study (2013) Voucher cited: R.O. Gardner 6186 (AK, K) Cultivated as an ornamental and sometimes seeding itself
Chile (offshore islands) Juan Fernández Islands	Isla Más a Tierra (Robinson Crusoe Island)	introduced invasive cultivated	Atkinson, Rachel/Sawyer, John (2011)
Chile (offshore islands) Juan Fernández Islands	Isla Más a Tierra (Robinson Crusoe Island)	introduced invasive	Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (pp. 461, 465, 550)
Chile (offshore islands) Juan Fernández Islands	Isla Más Afuera (Alejandro Selkirk Island)	introduced invasive	Atkinson, Rachel/Sawyer, John (2011)
Chile (offshore islands) Juan Fernández Islands	Isla Más Afuera (Alejandro Selkirk Island)	introduced invasive	Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (pp. 461, 465, 550) Voucher cited: Danton G(1474bis)1239bis
French Polynesia Society Islands	Tahiti Island	introduced cultivated	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Cultivée

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)	New South Wales	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Australia Australia (continental)	Australia (continental)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013) Australian Capital Territory, Tasmania, Victoria
Central America Central America (Pacific rim)	Costa Rica (Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
Central America Central America (Pacific rim)	Guatemala (Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
China China	China (People's Republic of)	introduced cultivated	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013) Fujian, Guangxi, Guizhou, Sichuan, Yunnan, Zhejiang
China China	Hong Kong	introduced cultivated	Wu, Te-lin (2001) (pp. 129-130)
Japan Japan	Japan	introduced	Mito, Toshikazu/Uesugi, Tetsuro (2004) (p. 184)
New Zealand New Zealand	New Zealand (country)	introduced invasive	Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 705)
South America (Pacific rim) South America (Pacific rim)	Chile (Republic of)	introduced invasive	Belov, Michail (2013) "This is an exotic plant, very invasive in central areas of Chile".
Taiwan Taiwan Island	Taiwan Island	introduced cultivated	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013)
United States (west coast) United States (west coast states)	USA (Oregon)	introduced	U.S. Dept. Agr., Agr. Res. Serv. (2013)
United States (west coast) United States (west coast states)	USA (California)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013)

Indian Ocean
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
La Réunion (France) La Réunion Island	La Réunion Island	introduced invasive cultivated	Comité français de l'Union Internationale pour la Conservation de la Nature en France (2013) foresterie, envahissant
Mauritius Mautitius Islands (Mauritius and Rodrigues)	Mauritius Island	introduced	ILDIS Co-ordinating Centre (2013)

Control:  "Mechanical control is achieved by ringbarking or digging out, chemical control by basal stem treatments, stump treatments, or foliar spray with herbicides.  After clearing large infestations, a follow-up programme is necessary to remove emerging seedlings and to prevent coppice regrowth.  Stumps need to be treated with herbicides in order to prevent resprouting, and it is recommended to keep stumps lower than 15 cm"  (Weber, 2003; p. 14).