\"This thorny, deciduous shrub grows to 4 metres in height, sometimes forming impenetrable thickets, although in most areas it forms a more open cover\" (Smith, 1985. In PIER, 2002). \"Erect much-branched shrub; leaves with 4-8 pairs of pinnae, pinnae with 10-12 pairs of small asymmetric leaflets ; stipular thorns straight and slender; flowers in pedunculate axillary heads, 1-3 heads together, subglobose; flowers yellow, fragrant; heads about 1-1,5cm across; stamens numerous; pods dark brown or black, up to 8cm long, to 12mm broad, plump, often slightly curved; pulp within sweetish; seeds compressed, elliptic, brown\" (Stone, 1970, in PIER, 2003) (differences according to Paiva, 1999).

In Hawaii Acacia farnesiana was formerly cultivated for an attempted perfume industry. It is now naturalised and common, sometimes becoming a pest in dry, open, disturbed areas, 2-400m (Wagner et al., 1999. In PIER, 2002). Although the aerial portions of the plant may be killed by fire, it soon regenerates from basal shoots, (Smith, 1985. In PIER, 2002). In Spain Acacia farnesiana is naturalised in rocky, poor soils (Paiva, 1999)

A tree of economic importance in South and East Africa, Rhodesia, India and the Rio Grande do Sul area of South America (Duke, 1983). The bark and the pods are a source of tannin and are used for tanning and dying leather (University of Connecticut, 2003). The flowers provide a fragrant essential oil which is used in the perfume industry as a violet scent substitute (Le Hou'erou, 2002). A gummy substance obtained from the pods is used in Java as cement for broken crockery. Other parts of the plant are used as an ingredient in the Ivory Coast for arrow poison (University of Connecticut, 2003). Trees add nitrogen and organic material, which improve the soil and are sometimes used for erosion control on poor sloping soils unsuitable for agriculture (Duke, 1983). Products are often used in folk medicine as styptics or astringents (Duke, 1983). In India and some African countries the pods are used as substitute for tamarind Tamarindus indica L. (Paiva, 1999). Cultivated in S.W. Europe for ornamental purposes and for perfumery industry (Tutin et al, 1992).

Acacia farnesiana thrives in dry localities and on loamy or sandy soils where it may serve as a sand binder (ranging from warm temperate dry through tropical desert to moist forest life zones, Acacia farnesiana is reported to tolerate annual precipitation of 6.4 – 40.3 dm (a mean of 20 cases is 14.0 dm), annual mean temperature of 14.7–27.8°C (mean of 20 cases = 24.1°C), and pH of 5.0–8.0 (mean of 15 cases = 6.8) (Duke, 1983). Dry habitats between sea level and 1000m (PIER, 2002). Smith (1985 In PIER, 2002) reports that\r\nalthough the aerial portions may be killed by fire, this plant soon regenerates from basal shoots.

It is a prolific seed producer (Scifres, 1974). The seeds readily germinate after soil disturbance and plants grow rapidly (Mutz et al., 1978, Land Protection, 2001). Seeds are dispersed by ungulates which eat the pods (PIER, 2002).

Acacia farnesiana can fix atmospheric nitrogen through symbiotic relation with Rhizobium allowing growth in nitrogen poor soils. Thrives on poor, dry soils but favours deeper, moister, more fertile soils (Duke, 1983).

In Hawaii, formerly cultivated for an attempted perfume industry (Wagner et al., 1999. In PIER, 2002)

Acacia farnesiana can spread readily and grow quickly, (Land Protection, 2001). As it often forms thorny thickets along some watercourses in Australia, it can be a considerable nuisance during mustering and can also hinder access to water (Land Protection, 2001). While access is less of a problem in areas where cattle graze on the mimosa, they readily eat the nutritious seed pods assisting its spread.

Preventative measures: A Risk Assessment of Acacia farnesiana for Hawai‘i and other Pacific islands was prepared by Dr. Curtis Daehler (UH Botany) with funding from the Kaulunani Urban Forestry Program and US Forest Service. The alien plant screening system is derived from Pheloung et al. (1999) with minor modifications for use in Pacific islands (Daehler et al. 2004). The result is a score of 14 and a recommendation of: \"Likely to cause significant ecological or economic harm in Hawai‘i and on other Pacific Islands as \r\ndetermined by a high WRA score, which is based on published sources describing species biology and behaviour in Hawai‘i and/or other parts of the world.\"

Physical: \"Destroyed by cultivation and grubbing\" (Swarbrick, 1997. In PIER, 2002). Although the aerial portions may be killed by fire, it soon \r\r\nregenerates from basal shoots\"\" (Smith, 1985). Once established, the seedlings grow rapidly and resprout readily following damage or top removal. Acacia \r\r\nfarnesiana sprouts may grow to almost half their original total plant height within 5 months after shredding (Powell et al., 1972). Thus, mechanical top \r\r\nremoval results in only short-term suppression of A. farnesiana (Mutz et al. 1978) and gives the species competitive advantage over associated, slower \r\r\ngrowing woody plants. Almost pure, dense stands of A. farnesiana may develop within two to three growing seasons following brush control methods that \rdisturb the soil.\r\n

Chemical: Probably susceptible to translocated herbicides, including picloram, metsulfuorn-methyl, glyphosate and triclopyr, and possibly 2,4-D applied to the foliage, freshly cut stumps or by stem injection at standard rates.
Also probably susceptible to residual herbicides, including tebuthiuron and hexazinone (Swarbrick, 1997 in PIER, 2002). \"Sensitive to foliar applications of triclopyr at 1 lb/acre and metsulfuron at 0.45 oz/a and to basal bark applications of 2,4-D or triclopyr at 2% in diesel. Drizzle applications were not effective in foliar and basal bark trials at Kihei, Maui, but these trials were confounded by a severe drought\" (Motooka et al. 2002. In PIER, 2002).