Performance of Piptatherum miliaceum (Smilo grass) in edaphic Pb and Zn phytoremediation over a short growth period

In a general screening of some mining areas in SE Spain for wild and autochthonous plant species with the potential to accumulate zinc and lead, of which some classified as accumulators were able to accumulate large concentrations of metal (>1000 mg kg−1) dry matter. Several Mediterranean taxa showed moderately enhanced heavy-metal accumulation and tolerance, e.g. Piptatherum miliaceum (L.) Cosson, or Smilo grass. This could be considered a Pb hyperaccumulator, being most efficient at removing and accumulating Pb from contaminated soil, and also efficient in Zn extraction. When soils were polluted with both metals, accumulation of Pb was greater. Results indicated that concentration of metal in the plant was directly correlated with that of the soil, although the transfer factors for Pb and Zn were not high. Most plants remained healthy for 3 weeks after introduction of pollutants.