A cardinal organ part that releases water through a hydathode pore. [source: ISBN:0471244554]
Comment
Hydathodes may have one or more pores that are similar to stomata but lack the ability to open and close. Hydathodes are involved in the release of water or xylem sap through pores via guttation or secretion. Generally, hydathodes are located at the end of a minor vein in a phyllome. In many plants, hydathodes includes a portion of thin-walled parenchyma between the tracheary elements and the pore, known as an epithem. In some plants, hydathodes are associated with secretory tissue.