The salt glands of Glaux maritima are regularly distributed on the adaxial and abaxial leaf surface. The gland consists of three cell types: a collecting cell, a stalk cell and secretory cells. The collecting cell is characterized by a large central vacuole, containing electron-dense material. The stalk cell contains many small vesicles and is connected with both the collecting cell and the secretory cells by numerous plasmodesmata. The secretory cells possess a strongly infolded plasmamembrane (cell wall protuberances) which could facilitate rapid ion transport to the subcuticular space. The large number of mitochondria in the secretory cells suggests energy-requiring steps in ion transport. The chloroplast-free stalk cell and the secretory cells may be supplied with energy by transport across the numerous plasmodesmata. It is speculated that small (pinocytotic) vesicles are involved in ion transport in the salt gland.