Abscission

Abscission (from the Latin ab, meaning away, and scindere, meaning to cut) is the shedding of various parts of an organism, such as a plant dropping a leaf, fruit, flower, or seed. In zoology, abscission is the intentional shedding of a body part, such as the shedding of a claw, husk, or the autotomy of a tail to evade a predator. In mycology, it is the liberation of a fungal spore. In cell biology, abscission refers to the separation of two daughter cells at the completion of cytokinesis.

In plants

Function

A plant will abscise a part either to discard a member that is no longer necessary, such as a leaf during autumn, or a flower following fertilisation, or for the purposes of reproduction. Most deciduous plants drop their leaves by abscission before winter, whereas evergreen plants continuously abscise their leaves. Another form of abscission is fruit drop, when a plant abscises fruit while still immature, in order to conserve resources needed to bring the remaining fruit to maturity. If a leaf is damaged, a plant may also abscise it to conserve water or photosynthetic efficiency, depending on the 'costs' to the plant as a whole. The abscission layer is a greenish-grayish color.