L., Fabaceae |
Present on Pacific Islands? yes
Primarily a threat at high elevations? no
Risk assessment results:
Reject, score: 23 (Go to the risk assessment (Australia))
High risk, score: 25 (Go to the risk assessment (Pacific))
Reject, score: 27 (Go to the risk assessment (U.S. (Florida)))
Other Latin names: Mimosa hispida Willd.; Mimosa pellita Humb. & Bonpl. ex Willd.
Common name(s): [more details]
English: amourette, bashful plant, black mimosa, catclaw mimosa, dormilona, giant mimosa, giant sensitive-plant, giant sensitive-tree, sensitive-plant, thorny sensitive-plant, zaraz |
French: amourette riviére |
Habit: shrub
Description: "Shrub, height to 6 m, stems armed with broad-based prickles up to 7 mm long. Leaves bipinnate, sensitive to touch. Straight, erect or forward pointing, prickle at the junction of each of the 6-14 pairs of pinnae and sometimes with stouter spreading or deflexed prickles between the pairs. Leaflets 20-42 pairs per pinna, linear-oblong, 3-8 (-12.5) mm long, 0.5-1.25 (-2) mm wide, venation nearly parallel with midrib, margins often bearing minute bristles. Inflorescence of tight, subglobose pendunculate heads 1 cm in diameter, each head containing ca 100 flowers, produced 1-2 (-3) together in the upper axils. Flowers mauve or pink, calyx minute, laciniate, 0.75-1 mm long; corolla about 2.25-3 mm long, stamens 8. Pods clustered, brown, densely bristly all over, breaking transversely into about 21 (14-26) partially dehiscent segments, each containing a seed, the pod sutures persisting as an empty frame. Seeds light brown to brown or olive green, oblong, light, dispersed by water and floating for an indefinite period" (Cronk & Fuller, 1995; pp. 90-95).
Habitat/ecology: Wet places in the humid and subhumid tropics. Favors climates with a dry season. "Grassland, freshwater wetlands, riparian habitats, wet forests. This nitrogen-fixing shrub establishes readily after disturbance and forms thorny, impenetrable thickets over large areas that exclude all other species. It shades out native tree seedlings in invaded swamp forests and transforms various wetland communities into pure stands with reduced bird and plant species richness" (Weber, 2003; p. 271).
In Australia, "swampy areas, e.g. flood plains; along watercourses. It forms dense impenetrable thickets which exclude native plants and animals, transforming sedgeland and grassland on flood plains into monotonous tall shrublands." (Smith, 2002; p. 33).
Propagation: Water-dispersed seeds. Seeds may remain dormant for many years. A prolific seed producer. "Pod segments float and are dispersed by water. They are also dispersed by humans and animals in mud adhering to fur, clothing or vehicles. Dispersal also aided by adventitious rooting." (Smith, 2002; p. 33).
Native range: Mexico, Caribbean islands, Central and South America, Africa including the Comoros, Madagascar, and Mauritius (GRIN).
Presence:
Pacific | |||
Country/Terr./St. & Island group |
Location |
Cited status &
Cited as invasive & Cited as cultivated & Cited as aboriginal introduction? |
Reference &
Comments |
Papua New Guinea
Papua New Guinea (eastern New Guinea Island) |
Papua New Guinea (eastern New Guinea Island) | Waterhouse, D. F. (1997) (p. 63) |
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) |
Northern Territory |
introduced
invasive |
Smith, Nicholas M. (2002) (p. 33) |
Australia
Australia (continental) |
Northern Territory |
introduced
invasive |
Australian Biological Resources Study (2013)
"Grows in clay, sandy loam and lateritic soil along watercourses, margins of mangrove swamps and coastal salt flats". |
Australia
Australia (continental) |
Queensland |
introduced
invasive |
Smith, Nicholas M. (2002) (p. 33)
Subject of an eradication program. |
Cambodia
Cambodia |
Cambodia (Kingdom of) |
introduced
invasive |
Waterhouse, D. F. (1993) (pp. 67, 78) |
Central America
Central America (Pacific rim) |
Costa Rica (Republic of) |
native
|
U.S. Dept. Agr., Agr. Res. Serv. (2013) |
Central America
Central America (Pacific rim) |
El Salvador (Republic of) |
native
|
U.S. Dept. Agr., Agr. Res. Serv. (2013) |
Central America
Central America (Pacific rim) |
Guatemala (Republic of) |
native
|
U.S. Dept. Agr., Agr. Res. Serv. (2013) |
Central America
Central America (Pacific rim) |
Honduras (Republic of) |
native
|
U.S. Dept. Agr., Agr. Res. Serv. (2013) |
Central America
Central America (Pacific rim) |
Nicaragua (Republic of) |
native
|
U.S. Dept. Agr., Agr. Res. Serv. (2013) |
Central America
Central America (Pacific rim) |
Panama (Republic of) |
native
|
U.S. Dept. Agr., Agr. Res. Serv. (2013) |
China
China |
Hong Kong |
introduced
invasive |
Wu, Te-lin (2001) (p. 132)
Along roadside. |
Indonesia
Indonesia |
Indonesia (Republic of) |
introduced
invasive |
Waterhouse, D. F. (1994) (p. 147) |
Malaysia
Malaysia |
Malaysia (country of) |
introduced
invasive |
Waterhouse, D. F. (1993) (pp. 67, 78) |
Mexico
Mexico |
Mexico (United Mexican States) |
native
|
U.S. Dept. Agr., Agr. Res. Serv. (2013) |
Singapore
Singapore |
Singapore (Republic of) |
introduced
invasive |
Waterhouse, D. F. (1993) (pp. 67, 78) |
Singapore
Singapore |
Singapore (Republic of) |
introduced
invasive |
Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 61)
Naturalised |
South America (Pacific rim)
South America (Pacific rim) |
Colombia |
native
|
U.S. Dept. Agr., Agr. Res. Serv. (2013) |
South America (Pacific rim)
South America (Pacific rim) |
Ecuador (Republic of) (continental) |
native
|
U.S. Dept. Agr., Agr. Res. Serv. (2013) |
South America (Pacific rim)
South America (Pacific rim) |
Perú (Republic of) |
native
|
U.S. Dept. Agr., Agr. Res. Serv. (2013) |
Thailand
Thailand |
Thailand (Kingdom of) |
introduced
invasive |
Waterhouse, D. F. (1994) (p. 147) |
Vietnam
Vietnam |
Vietnam (Socialist Republic of) |
introduced
|
ILDIS Co-ordinating Centre (2013) |
Indian Ocean | |||
Country/Terr./St. & Island group |
Location |
Cited status &
Cited as invasive & Cited as cultivated & Cited as aboriginal introduction? |
Reference &
Comments |
Comoros
Comoro Islands |
Comoro Islands |
native
|
U.S. Dept. Agr., Agr. Res. Serv. (2013) |
Mauritius
Mautitius Islands (Mauritius and Rodrigues) |
Mauritius Island |
native
|
U.S. Dept. Agr., Agr. Res. Serv. (2013) |
Comments: On exclusion lists for Hawaii, US, and French Polynesia. A problem species in Thailand. A "weed of national significance" in Australia and a declared noxious weed in Queensland, Northern Territory and Western Australia (Smith, 2002; p. 33).
Planting of this species in the State of Florida (U.S.) is prohibited by Florida Department of Environmental Protection (Hunsberger, 2001).
Control:
Physical: Because there is little grassy understorey in thickets of M. pigra, it is difficult to destroy infestations with fire without applying fuel such as gelled gasoline from aircraft. Follow-up control must then be carried out, because, although seeds on the soil surface are destroyed, germination of seeds from the seed bank, within 5 cm of the soil surface, is enhanced. (FAO)
Chemical: Various chemical control methods are described in the literature cited.
Biological: Six natural enemies have been released in Australia following rigorous host-specificity testing, but have not yet had any discernible effect. Four of these have also been released in Thailand. The six include two seed-feeding bruchid beetles, one stem-feeding chrysomelid beetle, two stem-boring moths and, in January 1992, a flower-feeding weevil. (FAO)
"For long-term control, biological methods are probably the most cost-effective considering the extent and ecology of this species. Palatability to higher animals is low, but in its native range it is attacked by more than 200 species of insect herbivores and fungal pathogens. The first insects introduced to Australia as controlling agents were the seed-feeding beetles Acanthoscelides quadridentatus and A. puniceus (Bruchidae) from Mexico. They were released in Australia in 19845 and 1985, respectively, but have not attained high population densities and have had little impact on seed production. Two stem-boring moths, Neurostrota gunniella (Gracillariidae) and Carmenta mimosa (Sesiidae), were released in Australia in 1989; of these, N. gunniella established readily. The young larvae mine leaf pinnules and the older larvae tunnel in the stems, causing them to die. Carmenta mimosa complements the action of N. gunniella by tunneling stems of larger diameter. Other important insects currently being tested for their host specificities in Mexico and Australia are the seed- and flower-feeding weevils Apion sp., Chalcodermus serripes, Sibinia fastigiata, S. ochreosa, S. pervana and S. seminicola.
"Two fungal pathogens, Phloeosporella sp. (Coelomycetes), and a rust, Diabole cubensis (Uredenales), severely debilitate Mimosa pigra in Mexico. Phloeosporella sp. attack leaves, branches, main stems and seed pods, causing leaf fall and cankers of the stems and leading to ring barking and die-back. Diable cubensis causes chlorosis in stems and leaves resulting in premature leaf fall. Both fungi are attacked by hyperparasitic fungi in their native range and it seems likely that their effect on Mimos pigra could be even more damaging in Australia if they were to be introduced without their natural enemies. These fungi are under investigation in Mexico and Britain" (Cronk & Fuller, 2001; p. 94).
See Waterhouse (1994; pp. 149-156) for natural enemies of the species and summaries of attempts at biological control.