Taxonomic name: Mimosa pudica (L.)
Synonyms: Mimosa pudica L. var. tetranda (Willd.) DC., Mimosa pudica L. var. unijuga (Duch. and Walp.) Griseb, Mimosa tetranda Humb. and Bonpl. ex Willd., Mimosa unijuga Duch. and Walp.
Common names: action plant (Australia), Almindelig mimose (Danish), attaapatti (Telugu), betguen sosa (Guam), chuimui (Hindi), co gadrogadro (Fiji), cogadrogadro (Fiji), dorme, dormidera, Gemeine Mimose (German), honteuse, humble plant (Australia), khadiraka (Sanskrit), Kruidje-roer-me-niet (Dutch), laajaalu (Sanskrit), laajak (Bengali), laajari (Marathi), la'au fefe (American Samoa/Samoa), Lajaalu (Hindi), lajja (India), lajjalu (India), lajjavanthi (Hindi), lajjavathi (Bengali), lajouni (Hindi), lazza bati (Bangladesh), limemeihr (Pohnpei Island), live and die (Australia), marie-honte, mateloi (Tonga), mayhont, mechiuaiu (Palau), memege (Niue), mimosa (Australia), morivivi, muttidare muni (Kannada), namaskaar (Sanskrit), ngandrongandro (Fiji), paope ‘avare (Ngaputoru Island), pikika‘a (Aitutaki Atoll), pikika‘a (Palmerston (Avarau) Island), pohe ha‘avare (Society Islands), pope ha'avare (Society Islands), pua hilahila (Hawaii), puteri malu (Brunei), rakau ‘avare (Atiu Island), rakau ‘avarevare (Ngaputoru Island), rakau pikika‘a (Mangaia Island), rakau pikika‘a (Rarotonga Island), Raktapaadi (Sanskrit), reesamani (Gujarati), samangaa (Sanskrit), sensitiva (Spanish), sensitiva, sensitive (French), sensitive grass (English), sensitive plant (English), shamebush (Australia), shamelady (Australia), shameplant (English), shameweed (Australia), shamipatra (Sanskrit), Sinnpflanze (German), sleeping grass (English), tho kandrodandro (Lau Island), tho ngandrongandro (Fiji), thothae jegri (India), ti mawi, tiare pikika‘a (Cook Islands), tita ‘avarevare (Ma'uke Island), tita ‘avarevare (Miti'aro Island), tita pikika‘a (Cook Islands), togop-togop (Sabah, Malaysia), tottalavaadi (Tamil), touch-me-not, tuitui (American Samoa), tuitui (Samoa), tuntokasvi (Finnish), vao fefe (American Samoa), vao fefe (Samoa), vao tuitui (Samoan), vergonzosa (Australia)
Organism type: herb
Mimosa pudica is native to South America, but has become a pan-tropical weed. It was introduced to many countries as an ornamental plant and is still widely available for sale. Mimosa pudica has become a pest in forest plantations, cropland, orchards and pasture. Mimosa pudica is used as a medicinal plant in many regions.
Mimosa pudica is a more or less prostrate creeper; with cylindric stems reddish-brown, prickly; leaves immediately fold by pulvini if touched or jarred; pinnae 4, often reddish; leaflets 12-25 pairs, linear, acute, bristly; 9-12mm long, 1.5mm wide; flowers pink, in globose heads, nearly 1cm in diameter, axillary, peduncle up to 2.5cm long; pods crowded, flat, prickly-bristly, indented between the few (2-4) seeds, to nearly 2cm long; seeds about 2mm broad, rounded, brown (Stone, 1970; in PIER, 2005; CSIS, undated). It may reach up to 1 metre in height, although it usually grows 15-45cm high (CSIS, undated; Francis, undated; Land Protection, 2006). It is described variously as an annual, biennial or perennial plant (Wu et al., 2003; USDA, 2006; PIER, 2005).
agricultural areas, planted forests, ruderal/disturbed, urban areas
Mimosa pudica occurs in croplands, orchards, pastures, mowed areas, roadsides, areas disturbed by construction, moist waste ground, open plantations, and weedy thickets (PIER, 2005; Francis, undated). It may grow as a single plant or in tangled thickets. M. pudica grows from near sea level up to 1,300m in elevation (Holm et al., 1977; in Francis undated) and in areas with annual precipitations from about 1000 to over 2000mm. It is frost-sensitive (Francis, undated).
M. Pudica is shade intolerant and does not compete with tall vegetation or grow under forest canopies. The species’ roots produce carbon disulfide, which selectively inhibits colonization of the rhizosphere by mycorrhizal and pathogenic fungi (Feng et al., 1998; in Francis, undated). M. Pudica is primarily found on soils with low nutrient concentrations, as it is probably outcompeted on richer soils (Magda et al., 2006). It grows on most welldrained soils, even scalped or eroded subsoils. It requires disturbed soils to establish itself. Repeated burning may encourage its spread in pastures (Siregar et al., 1990; in Francis, undated).
Mimosa pudica forms a dense ground cover, preventing reproduction of other species (PIER, 2005). It has become a serious weed in fields of corn, soybeans, tomatoes, upland rice, cotton, bananas, sugarcane, coffee, oil palms, papayas, coconuts, and rubber in many tropical areas. It is particularly troublesome where hand pulling of weeds is practiced, as its thorns can cause painful wounds. On the other hand, it is tolerated or valued as a forage plant in pastures (Holm et al., 1977, Turbet and Thuraisingham, 1948; in Francis, undated). In fact, sheep grazing is reported to control M. pudica in pastures and plantations (Simonnet, 1990; in Francis,undated). The root nodules have been shown to fix nitrogen (Pokhriyal et al., 1990; in Francis, undated). Thickets of M. pudica may be a fire hazard when dry (PIER, 2005).
The seeds and other plant parts of M. pudica contain mimosine, and extracts of the plant have been shown in scientific trials to be a moderate diuretic, depress duodenal contractions similar to atropine sulphone, promote regeneration of nerves, and reduce menorrhagia. Antidepressant activity has been demonstrated in humans (Martínez et al.,1996). Root extracts are reported to be a strong emetic (Guzmán, 1975) (all from Francis, undated). M. pudica is used as a part of traditional medicine in SE and S Asia (Biswas and Mukherjee, 2003; Amitendu et al., 2004; Rajan et al., 2002; Ahmad and Holdsworth, 2003). See here for details on the ethnobotanical uses of M. pudica.
M. pudica is also a popular ornamental plant, as its leaves will fold up when stimulated by touch, heat or wind (Whatcom Seed Company, 2006; GRIN, 2006), and is also used for soil improvement (GRIN, 2006).
When touched, an Mimosa pudica plant quickly folds its leaflets and pinnae and droops downward at the petiole attachment. The leaves also droop at night, and when exposed to rain or excessive heat. This response may be a defense against herbivorous insects, leaching loss of nutrients, or desiccation (Francis, undated).
M. pudica has been identified as having potential for phytoremediation of arsenic polluted areas in Thailand (Visoottiviseth et al., 2002).
First described from Brazil, now a pan-tropical weed (PIER, 2005).
Native range: Belize, Brazil, Colombia, Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Peru.
Known introduced range: USA, Fiji, Papua New Guinea, Tonga, New Caledonia, Samoa, American Samoa, Northern Mariana Islands, Cook Islands, Galapagos Islands, Federated States of Micronesia, French Polynesia, Guam, Marshall Islands, Nauru, Niue, Palau, Solomon Islands, Tokelau, Vanuatu, Wallis and Fatuna, Australia, Cambodia, China, Indonesia, Japan, Malaysia, Brunei, Philippines, Singapore, Taiwan, Thailand, Vietnam, British Indian Ocean Territory, La Réunion, Maldives, Mauritius, Rodrigues, Seychelles, Hong Kong, India, Bangladesh, Sri Lanka, Guinea, Nigeria.
Status unknown: Cuba, French Guiana, Puerto Rico, US Virgin Islands.
Introduction pathways to new locations
Other: Seed pods float and are spread by water (Smith, 2002; in PIER, 2005).
Local dispersal methods
On animals: Pods can be spread by attaching to fur (Smith, 2002; in PIER, 2005).
On clothing/footwear: Pods can be spread by attaching to clothing (Smith 2002; in PIER, 2005).
Other (local): Pods can be spread by attaching to clothing (Smith 2002; in PIER, 2005).
Road vehicles: Pods can be spread by mud on vehicles (Smith, 2002; in PIER, 2005).
Water currents: Seed pods float and are spread by water (Smith, 2002; in PIER, 2005).
Preventative measures: A Risk assessment of Mimosa pudica for the Pacific region was prepared by Pacific Island Ecosystems at Risk (PIER) using the Australian risk assessment system (Pheloung, 1995). The result is a score of 18 and a recommendation of rejection for import into Australia.
A Risk assessment of Mimosa pudica for Florida was prepared by Gordon et al 2008. The result is a score of 17 and a recommendation of rejection for import into Florida.
Physical: Hand weeding is difficult due to the presence of thorns and a woody root (Wagner, 1983; in PIER, 2005). Repeated burning may in fact encourage the spread of M. pudica in pastures (Magda et al., 2006).
Chemical: It is susceptible to several herbicides, including dicamba, glyphosate, picloram and triclopyr (Parsons and Cuthbertson, 1992). Very sensitive to picloram (0.25 lb/acre), sensitive to triclopyr. Dicamba and 2,4-D poor. Soil applied tebuthiuron effective (Motooka et al., 2002) (all from PIER, 2005).
In pasture situations, dicamba and fluroxypyr can be used to control M. pudica. Thorough wetting of all leaf surfaces is essential. If plants are disturbed before spraying, the leaves will fold up and the herbicide will be ineffective. Ensure all spraying is done with forward booms or ahead of operators with knapsack sprayers (Land Protection, 2006).
Biological: See Waterhouse and Norris (1987) and Waterhouse (1994) for information on prospective biological control agents (PIER, 2005).
Coir dust, a waste from coconut processing, can be used as a mulch in pineapple crops to suppress M. pudica and other weeds (Van Mele et al., 1996).
Sheep grazing is reported to control the dominance of M. pudica in pasture (Magda et al., 2006; Francis, undated).
In the Philippines, Mimosa pudica flowers all year round, and may produce as many as 675 seeds per plant per year (Holm et al., 1977). The species is both wind (Chieng and Huang, 1998) and bee-pollinated (Payawal et al., 1991). Air-dry seeds from Puerto Rico weighed an average of 0.0065 + 0.0002 g/seed. Seeds are transported by means of the bristles on the edges of their pods that cling to clothing or to the fur of mammals (Francis, undated).
In Puerto Rico, M. pudica plants live 1 to 2 years. Seedlings grow slowly for 2 or 3 months and then accelerate, reaching 0.5 to 2m of extension at the end of the first year. Growth of plants that survive into the second year is much slower. Potted and fieldgrown individuals are sensitive to overwatering (Bui, 2001). This species has been successfully tested and recommended for erosion control plantings using potted material at a spacing of 60 x 60cm (Coimbra and Magnanini ,1953) (all from Francis, undated).
In China, the flowering season from March to October, with fructescence from May to November (CSIS, undated).
Compiled by: IUCN SSC Invasive Species Specialist Group
Updates with support from the Overseas Territories Environmental Programme (OTEP) project XOT603, a joint project with the Cayman Islands Government - Department of Environment
Last Modified: Monday, 4 October 2010