Tyloses

Tyloses are shown in a tangential longitudinal view of a secondary xylem vessel just under a wounded surface in a current-year stem of grape (Vitis vinifera L. cv Chardonnay). Tyloses are induced outgrowths from paratracheal parenchyma cells that block xylem vessels as a step in wound healing. The image is a bright field digital micrograph of a section cut with a sliding microtome and stained with safranin and fast green.