Hydathodes

adaptations in plants for the excretion of tiny droplets of moisture (guttation).

Hydathodes serve for the passive exudation of surplus water through the epidermal pores under the effect of root pressure. They are found primarily in plants with weak transpiration that live in conditions of excessive soil moisture. The hydathodes are located on the apexes of the leaves or on the tips of the laminar denticles. In the majority of plants they are modified stomata whose guard cells never close. The pore is sometimes surrounded by ordinary epidermal cells. Some hydathodes are actively moisture-excreting glandulae.