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Although iron deficiency is a serious plant stress for many cultivated plants grown in calcareous soils of arid regions, iron uptake by shrubs and forbs of wildland plant communities growing in alkaline soils of and regions seldom show iron-deficiency symptoms. Presumably these plants have developed iron-deficiency stress response mechanisms which have allowed them to successfully extract iron from soils which are normally considered to have low iron availability. This study examined the iron-stress responses exhibited by roots of six arid-zone shrubs, i.e. Fourwing Saltbush (Atriplex canescens), Silver Sagebrush (Artemisia cana), Rubber Rabbitbrush (Chrysothamnus nauseosus), Winterfat (Eurotia lanata), Prostrate Summer Cypress (Kochia prostrata), and Mediterranean Camphorfume (Camphorosma monspeliacum), and one forb, Small Burnet (Sanguisorba minor). One-year-old container-grown plants were transferred to nutrient solution culture and subjected to treatments with and without iron for a 21 d period during which solution pH and concentration of chemical reductants and reduction of iron by roots were measured. Plants stressed in iron-free solutions responded by lowering solution pH by releasing reductants into the solutions and by reducing iron at the roots. Root release of acids and iron reduction were visually observed by placing stressed roots on indicator treated agar plates and photographing color changes. Returning iron-stressed plants to solution cultures containing iron showed rapid greening of new tissues and cessation of the pH and reductant responses. Subsequent iron-deficiency stress reproduced the root release of hydrogen ions and reductants - often at higher intensities than during the initial iron-stress period.