Aims <p>Iron (Fe) deficiency severely limits crop growth in calcareous soils. Research into responses to Fe deficiency has focused chiefly on crops and model plants. Wild plants may exhibit natural variations in Fe uptake strategies that can be exploited for agricultural purposes and to understand species distribution.</p> Methods <p>To examine the plasticity of the Fe-deficiency response in plants adapted to various environments, we screened wild species in Fe-deficient medium for variations in root fluorescence as a readout for Fe nutritional status.</p> Results <p>Our results show that Fe deficiency triggered accumulation of coumarins in dicots as expected. However, <i>Veronica officinalis</i> and <i>Trifolium montanum</i> showed atypical responses; the former failed to accumulate coumarins and succumbed to even mild Fe deficiency, the latter showed constitutive Fe uptake responses&#xa0;and overaccumulated the coumarins fraxin and scopolin in both roots and shoots, even under Fe sufficiency. These adaptations coincided with the unusual natural distribution of these species: <i>V. officinalis</i> is restricted to constantly Fe-rich acid soils, whereas <i>T. montanum</i> grows on constantly Fe-limited calcareous soils.</p> Conclusion <p>This study indicates that exploiting soils within a&#xa0;wide pH range requires correct regulation of coumarin-based Fe acquisition.</p>