Halophytes tolerate high salinity levels that would kill conventional crops. Understanding salt tolerance mechanisms will provide clues for breeding salt-tolerant plants. Many halophytes such as quinoa (Chenopodium quinoa) are covered by a layer of epidermal bladder cells (EBCs) that are thought to mediate salt tolerance by serving as salt dumps. We isolated an epidermal bladder cell-free quinoa mutant (ebcf) that completely lacked EBCs and was mutated in REBC and REBC-like1. This mutant showed no loss of salt stress tolerance. When wild-type quinoa plants were exposed to saline soil, EBCs accumulated K + as the major cation, in quantities far exceeding those for Na + . Emerging leaves densely packed with EBCs had the lowest Na + content, whereas old leaves with deflated EBCs served as Na + sinks. When the leaves expanded, K + was recycled from EBCs, resulting in turgor loss that led to a progressive deflation of EBCs. Our findings suggest that EBCs in young leaves serve as a K + -powered hydrodynamic system that functions as a water sink for solute storage. Na + accumulates within old leaves that subsequently wilt and are shed. This mechanism improves the survival of quinoa under high salinity.