The effect of EDDHA (ethylenediamine-di-o-hydroxyphenylacetic acid) on growth and flowering of Lemna minor cultured in M-medium was investigated. It was observed that inclusion of this compound induced flowering in this plant. The maximum flowering was observed in a medium supplemented with 15 ppm of this metal chelate. Endogenous copper analysis of flowering and non-flowering plants demonstrated 45-65 % less copper in flowering plants, thereby indicating the role of copper in the flowering of L. minor.