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 con-taining 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.