Invasiveness Assessment Record Scientific name: Acacia farnesiana (L.) Willd. Common Name: mimosa bush QUESTION COMMENTS RATING CONFIDENCE Establishment 1. Germination Although scarification and other pretreatments of seeds increase germination rates, “seeds may be sown without MH requirements? pretreatment… germination takes place in the rainy season, but many seeds remain dormant for a full year before MH germinating” (Parrotta 1992) – requires natural seasonal disturbances such as seasonal rainfall for germination 2. Establishment “is intolerant of shade and requires free growing space” (Parrotta 1992) – requires more specific requirements to MH requirements? establish ML 3. How much disturbance “Grows in schlerophyll woodland, shrubland and grassland, on alluvial clay soils and sandy loams, on open plains MH is required? and near watercourses” (Harden 2002) and is also found growing by railways (Benson, McDougall 1996). It MH invades “pastures, fallow land and disturbed natural vegetation” (Foroughbakhch 1992) – establishes in relatively intact or minor disturbed natural ecosystems Growth/Competitive 4. Life form? Leguminous (Cervantes et al 1996) MH H

5. Allelopathic “Extracts from… A. farnesiana… caused moderate but significant inhibition [of Lemna aequinoctialis] with the MH properties? most inhibited growths … 32% (seed)” (Allan, Adkins 2005) – allelopathic properties seriously affecting some MH plants 6. Tolerates herb Leaves consumed by goats and sheep, although digested poorly in sheep (Ramirez, Ledezma-Torres 1997). Also H pressure? browsed by white-tailed deer (Ramirez et al 1997). However it is persistent “in heavily grazed, mechanically cut, MH and herbicide-treated pastures” (Parrotta 1992) – consumed but not preferred 7. Normal growth rate? “Increased constantly across each growing season so it ought to develop rapidly its photosynthetic surface” MH (Foroughbakhch 1992). “Under field conditions on semiarid sites, seedling heights after 1 year are typically 30 to H 50 cm” however if irrigated under nursery conditions, plants can grow to 210 cm in the first year (Parrotta 1992) – rapid growth rate (under ideal conditions) 8. Stress tolerance to “Drought hardy, fire resistant, and susceptible to frost… tolerates saline soils” (Parrotta 1992), however it shows H frost, drought, w/logg, high yields in an area where hail and frost occurs yearly (Foroughbakhch 1992) H sal. etc? Grows in a site that is subject to water logging, however this ‘restricts the normal plant growth’ (Goel, Behl 2004) Reproduction 9. Reproductive system “Prolific seed producer” (ISSG 2006) and “reportedly can be propagated vegetatively by cuttings. Although no M data are available on vegetative reproduction under field conditions, the persistence of aroma in heavily grazed, H mechanically cut, and herbicide-treated pastures suggests that the species coppices well” (Parrotta 1992) – sexual and possibly vegetative 10. Number of propagules Pods can contain between 11 and 23 seeds (Parrotta 1992) – above 2000 M produced? H

Acacia farnesiana Invasiveness.doc Page 1 of 2 August ‘08 Invasiveness Assessment Record Scientific name: Acacia farnesiana (L.) Willd. Common Name: mimosa bush QUESTION COMMENTS RATING CONFIDENCE 11. Propagule longevity? “seeds remain viable for 30 years or more when stored under dry conditions at ambient temperature” (Parrotta M 1992) H 12. Reproductive period? “may form dense thickets and become weedy” (Harden 2002) and is a “spreading, thicket-forming shrub” M (Richardson et al 2006) – species forms self-sustaining monocultures H 13. Time to reproductive “known to flower as early as the second year following germination, with pods produced as early as the third MH maturity? year” (Parrotta 1992) ML Dispersal 14. Number of “The leaves and pods are much eaten by stock, which probably aid in diffusion of the seeds” (Standley, H mechanisms? Streyermark 1946). On a regional scale seeds are dispersed by ocean currents (on which the seed pods can float H for up to 600 km), traders, planters and farmers and on a local scale planters, water, livestock and wind are responsible for dispersal (Kull, Rangan 2008) 15. How far do they the seed pods can float on ocean currents for 600 km (Kull, Rangan 2008) – very likely that at least one propagule H disperse? will disperse greater than one kilometre H

Acacia farnesiana Invasiveness.doc Page 2 of 2 August ‘08