In agreement with this, McGrath et al. (1997) found similar plant yield (DW) for N.caerulescens plants grown for 105 days in three different soils containing moderate to high levels of heavy metals (155–1317 g g−1Zn, 80–879 g g−1Pb, 2.9–16.5 g g−1Cd)—behaviour typical of metallophytes, which are able to develop normally in heavy metalpolluted soils.