scion

scion \SY-uhn\, noun:

1. A detached shoot or twig of a plant used for grafting.
2. Hence, a descendant; an heir.

Convinced he was the scion of Louis Alexandre Lebris de Kerouac, a noble Breton, he was off to do genealogical research in the Paris libraries and then to locate his ancestor's hometown in Brittany.
-- Ellis Amburn, Subterranean Kerouac

Sassoon, scion of a famously wealthy Jewish banking family, had never needed to earn his living.
-- Philip Hoare, Oscar Wilde's Last Stand

Gates is the scion of an old, affluent Seattle family; Jobs is the adopted son of a machinist in Northern California.
-- "Steve Jobs, Hesitant Co-Founder, Makes New Commitment to Apple", New York Times, August 7, 1997

Scion derives from Old French cion, of Germanic origin.