<P> 36 native Thai plant species were tested to see which conducted the most phytoremediation of arsenic polluted soils caused by tin mines . Mimosa pudica was one of the four species that significantly extracted and bioaccumulated the pollutant into its leaves . Other studies have found that Mimosa pudica extracts heavy metals such as copper, lead, tin, and zinc from polluted soils . This allows for the soil to gradually return to less toxic compositions . </P> <P> Mimosa pudica can form root nodules that are habitable by nitrogen - fixing bacteria . The bacteria are able to convert atmospheric nitrogen, which plants cannot use, into a form that plants can use . This trait is common among plants in the family Fabaceae . Nitrogen is a vital element for both plant growth and reproduction . Nitrogen is also essential for plant photosynthesis because it is a component of chlorophyll . Nitrogen fixation contributes nitrogen to the plant and to the soil surrounding the plant's roots . </P> <P> Mimosa pudica's ability to fix nitrogen may have arisen in conjunction with the evolution of nitrogen - fixing bacteria . Nitrogen fixation is an adaptive trait that has transformed the parasitic relationship between the bacteria and plants into a mutualistic relationship . The shifting dynamics of this relationship are demonstrated by the corresponding improvement of various symbiotic characteristics in both Mimosa pudica and bacteria . These traits include enhanced "competitive nodulation, nodule development, intracellular infection, and bacteroid persistence". As much as 60% of the nitrogen found in Mimosa pudica can be attributed to the fixation of N by bacteria . Burkholderia phymatum STM815 and Cupriavidus taiwanensis LMG19424 are beta - rhizobial strains of diazotrophs that are highly effective at fixing nitrogen when coupled with M. pudica . Burkholderia is also shown to be a strong symbiont of Mimosa pudica in nitrogen - poor soils in regions like Cerrado and Caatinga . </P> <P> In cultivation, this plant is most often grown as an indoor annual, but is also grown for groundcover . Propagation is generally by seed . Mimosa pudica grows most effectively in nutrient poor soil that allows for substantial water drainage . However, this plant is also shown to grow in scalped and eroded subsoils . Typically, disrupted soil is necessary in order for M. pudica to become established in an area . Additionally, the plant is shade intolerant and frost - sensitive, meaning that it does not tolerate low levels of light or cold temperatures . Mimosa pudica does not compete for resources with larger foliage or forest canopy undergrowth . </P>

Hawaiian plant that closes when you touch it