Phytoremediation combines the Greek word phyton, "plant," with the Latin word remediare, "to remedy," to describe a system whereby certain plants, working together with soil organisms, can transform contaminants into harmless and often, valuable, forms. This practice is increasingly used to remediate sites contaminated with heavy metals and toxic organic compounds.

Phytoremediation takes advantage of plants' nutrient utilization processes to take in water and nutrients through roots, transpire water through leaves, and act as a transformation system to metabolize organic compounds, such as oil and pesticides. Or they may absorb and bioaccumulate toxic trace elements, such as the heavy metals, lead, cadmium, and selenium. In some cases, plants contain 1,000 times more metal than the soil in which they grow. Heavy metals are closely related to the elements plants use for growth. In many cases, the plants cannot tell the difference, according to Ilya Raskin, Professor of Plant Sciences...