A zone of specialised cells extending across the base of a leaf, fruit, or flower. Towards the end of the growing season the pectin s in the cell walls of this layer are dissolved by enzymes and the cells separate.

A layer of cells that forms at the base of a fruit or leaf stalk where it is attached to the stem. The veins that carry nutrients and water into and out of the structure become closed off, and the fruit or leaf will eventually fall off. See full slip and half slip

layer of cells that forms at the base of each leaf petiole where it is attached to the twig when the veins that carry fluids into and out of the leaf gradually close off.