Mimosa diplotricha (vine, climber, shrub)

Ecology Distribution Management Info Impact Info References and Links Contacts

Taxonomic name: Mimosa diplotricha C. Wright ex Sauvalle Synonyms: Mimosa invisa Common names: co gadrogadro (Fiji), giant false sensitive plant, giant sensitive plant (English), grande sensitive (French), la'au fefe palagi (Samoa), la'au fefe tele (Samoa), limemeihr laud (Pohnpei), mechiuaiuu (Palau), nila grass (English), pikika‘a papa‘a (Cook Islands), sensitive gèante (French), singbiguin sasa (Saipan), vao fefe palagi (American Samoa and Samoa), wa ngandrongandro levu (Fiji), wa ngandrongandro ni wa ngalelevu (Fiji) Organism type: vine, climber, shrub Mimosa diplotricha (also referred to in the literature as Mimosa invisa) is a serious weed around the Pacific Rim, where it is the subject of several eradication programmes. Early detection and control is recommended to prevent large infestations from establishing. Description Mimosa diplotricha is a shrubby or sprawling annual vine which may also behave as a perennial. Its stems are bunching, often scrambling over other plants. Additionally, they are distinguished by four-angles, each of which consisting a line of sharp, hooked prickles. Leaves are bright green, feathery and fern-like and are arranged in an alternating pattern, with each leaf divided into five to seven pairs of segments. Each segment carries about twenty pairs of very small leaflets which close up when disturbed or injured and at night (DPIF, 2007). Habitat description Mimosa diplotricha grows best in tropical regions: high moisture and in highly fertile soils. It is known to thrive under full sunlight conditions. M. diplotricha is naturalised in high rainfall areas of coastal north Queensland, Australia (DPIF, 2007). General impacts Mimosa diplotricha is a major weed of cultivated areas and has the ability to climb over other plants (Schultz 2000). In the Kaziranga National Park in northeast India, the weed forms a thorny mat over the natural vegetation, preventing animals from accessing and utilising natural vegetation (N. Gureja, pers. comm. 2003). In Australia the weed chokes out cane, other crops and grassland, causing crop and pasture loss (DPIF, 2007). Notes Mimosa diplotricha is still often referred to as Mimosa invisa in the literature. Geographical range Native Range: Mimosa diplotricha is native to Brazil (DPIF, 2007). Known introduced range: American Samoa, Commonwealth of the Northern Mariana Islands, Cook Islands, Federated States of Micronesia, Fiji, French Polynesia, Guam, New Caledonia, Niue, Palau, Papua New Guinea, Samoa, Solomon Islands, Vanuatu, Australia, Taiwan, Cambodia, Vietnam, Malaysia, Indonesia, Philippines, Christmas Island (Australia), La Réunion (France) and Mauritius. Introduction pathways to new locations Agriculture: M. diplotricha was imported into India by tea gardeners for enriching the soil as Mimosa species are nitrogen fixers. (N. Gurega, Pers. Comm. 2003). Road vehicles (long distance): M. diplotricha seeds are transported by running water, vehicles, machinery, stock and contaminated earth (The Department of Natural Resources, Mines and Water 2006). Translocation of machinery/equipment: M. diplotricha seeds are transported by running water, vehicles, machinery, stock and contaminated earth (The Department of Natural Resources, Mines and Water 2006). Transportation of domesticated animals: M. diplotricha seeds are transported by running water, vehicles, machinery, stock and contaminated earth (The Department of Natural Resources, Mines and Water 2006). Local dispersal methods Transportation of habitat material (local): M. diplotricha seeds are transported by running water, vehicles, machinery, stock and contaminated earth (The Department of Natural Resources, Mines and Water 2006). Water currents: M. diplotricha seeds are transported by running water, vehicles, machinery, stock and contaminated earth (The Department of Natural Resources, Mines and Water 2006). Management information Preventative measures: A Risk Assessment of Mimosa diplotricha for Hawaii 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 24 and a recommendation of: "Likely to cause significant ecological or economic harm in Hawai‘i and on other Pacific Islands as determined 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". A Risk assessment of Mimosa diplotricha for Australia was prepared by Rod Randall. The result is a score of 16 and a recommendation of: reject the plant for import (Australia) or species likely to be a pest (Pacific) (PIER, 2008). In Australia the best management approach to controlling M. diplotricha has been suggested to encompass a variety of different methods, including herbicide use and biological control (DPIF, 2007). Physical: Hand control is difficult due to spines. Plants can be slashed before seeding occurs. Slashing in pastures and other non-crop situations on a regular basis to prevent seeding provides effective control (DPIF, 2007). Chemical: Any herbicide that is applied should be done so before seeding occurs. The weed is not susceptible to soil fumigants and short-term residual herbicides, (although it may be temporarily controlled with atrazine, diuron and hexazinone at standard to high rates). It is susceptible to translocated herbicides including sodium arsenite, 2,4-D plus atrazine, fluroxypyr and probably glyphosate at standard rates. In non-grazed infested areas 4.5 mL Starane 200 per litre of water can be used (DPIF, 2007). More details of herbicide application may be found at DPIF, 2007. Biological: An introduced sap feeding bug, the psyllid Heteropsylla spinulosa has been released as a biocontrol agent for M. diplotricha in north Queensland, Austalia, in non-crop areas. Releases at Palikir, Pohnpei have also proven effective. (DPIF, 2007, Waterhouse 1994, in PIER 2008). In Australia it is recommended that pastures and non-crop infestations are assessed for insect abundance between November-April. (The effectiveness of insect control can be predicted by abundant insects prior to flowering commencing in early April). If insects are present in sufficient numbers, the growing tips and leaves are curled and stunted, resulting in no or minimal flower production. Slashing or herbicides should be applied if there are not sufficient numbers of insects prior to April for effective control. In pastures grazing animals tend to control this protein rich legume and prevent it dominating. Plants stunted by Heteropsylla attack are less spiny and are readily grazed by stock. An isolated strain of the stem-spot disease (Corynespora cassiicola) (indigenous to Australia) also appears specific to giant sensitive plant. One study noted that the citheroniid moth (Psigida walker) caused a significant extent of defoliation and the subsequent prevention of seeding of M. diplotricha in Brazil (Vitellia et al., 2001). However, it was shown that the citheroniid moth lacked the target specificity required as it attacked several native bipinnate Acacia species, thus was deemed unsuitable for release (Vitellia et al., 2001). Reproduction Mimosa diplotricha produces thousands of seeds (N. Gureja pers. comm. 2003). Seeds have been known to lie dormant for up to 50 years (DPIF, 2007). Lifecycle stages Mimosa diplotricha is an annual which usually flowers and seeds from April (autumn) through to the end of June (mid-winter) in Australia. In years when there has been very little cold weather, plants will seed from April through to December and some plants only 10cm high can set seeds (DPIF, 2007). Compiled by: IUCN/SSC Invasive Species Specialist Group (ISSG) To contribute information, please contact Shyama Pagad. Last Modified: Friday, 21 July 2006