1) top part of a graft. with leaves and buds. that is grafted to the stock or root stock. 2) woody tissue (that does not require buds) used to complete a bridge graft.
Merriam-Webster Online Dictionaryscion (noun)
a detached living portion of a plant (as a bud or shoot) joined to a stock in grafting and usually supplying solely aerial parts to a graft
a) - descendant child , especially a descendant of a wealthy, aristocratic, or influential family
b) - heir scion of a railroad empire