HORTICULTURE

Detailed explanation-1: -The upper part of the combined plant is called the scion (/ˈsaɪən/) while the lower part is called the rootstock . The success of this joining requires that the vascular tissues grow together and such joining is called inosculation.

Detailed explanation-2: -A scion is a piece of vegetative material that you will graft with, from a tree that produces the fruit variety you want. For grafting like whip and tongue, scions are collected in the winter when the trees are dormant.