Open English Wordnet
Nouns
(n)blackjack oak, blackjack, jack oak, Quercus marilandicaa common scrubby deciduous tree of central and southeastern United States having dark bark and broad three-lobed (club-shaped) leaves; tends to form dense thickets
(n)jack oak, northern pin oak, Quercus ellipsoidalissmall to medium deciduous oak of east central North America; leaves have sharply pointed lobes