from:http://en.wikipedia.org/wiki/Pistia
A plant is said to be a hyperaccumulator if it can concentrate the pollutants in a minimum percentage which varies according to the pollutant involved (for example: more than 1000 mg/kg of dry weight for nickel, copper, cobalt, chromium or lead; or more than 10,000 mg/kg for zinc or manganese).[10] This capacity for accumulation is due to hypertolerance, or phytotolerance: the result of adaptative evolution from the plants to hostile environments through many generations. A number of interactions may be affected by metal hyperaccumulation, including protection, interferences with neighbour plants of different species, mutualism (includingmycorrhizae, pollen and seed dispersal), commensalism, and biofilm.
from:http://en.wikipedia.org/wiki/Phytoremediation
| Cd–Cadmium | T- | Pistia stratiotes | Water lettuce | Cu(T), Hg(H), Cr(H) | Pantropical, Origin South U.S.A.; aquatic herb |
from:http://en.wikipedia.org/wiki/Hyperaccumulators_table_%E2%80%93_3
Old School Garden 