Intact and excised samples of corn root tissue were subjected to water stress either by incubation in solutions of osmotica or by desiccation, after which they were transferred to CaSO4 solution for various time periods for recovery. Osmotic agents used were either mannitol or polyethylene glycol 6000 at concentrations adequate to depress rubidium absorption to less than 30% of that of controls. During 6 h following release from osmotic stress, rubidium absorption by samples from intact seedlings treated with mannitol increased to 44% of that of controls, while those treated with polyethylene glycol increased to 79 % of that of controls. Recovery of root samples excised prior to stress was very nearly the same as that of samples from intact roots. When water stress was produced by desiccation, recovery was about the same as from polyethylene glycol, attaining a rate of 76% of that of controls after 8 h. Whereas desiccated samples almost completely regained their water content during recovery, none showed correspondingly complete recovery of ion absorption capacity. Finally, during the recovery period, the submerged controls, but not controls in humid air, showed an increase in ion absorption capacity with time, confirming that the widely observed "aging effect" or "washing effect" is due to submersion and not to time per se.