Toxicity data in sunflower callus cultures were determined for 12 metal ions: Ca(II), Cd(II), Co(II), Cu(II), K(I), Li(I), Mg(II), Mn(II), Na(I), Ni(II), Zn(II) and La(III). Based on fresh and dry weight measurements, in vitro EC50 values in solution and in callus tissue were determined. The correlations of the two toxicity data sets were modest. Pearson×s correlation analysis of the toxicity data set determined in callus tissue and numerous parameters