Tylosis (botany)

In woody plants, a tylosis (plural: tyloses) is a bladder-like distension of a parenchyma cell into the lumen of adjacent vessels. The term tylosis summarises the physiological process and the resulting occlusion in the xylem of woody plants as response to injury or as protection from decay in heartwood. It is a key process in wall one of the compartmentalization of decay in trees (CODIT) and other woody plants.