Main entry: Quercus ellipsoidalis, jack oak, northern pin oak
Definition: small to medium deciduous oak of east central North America; leaves have sharply pointed lobes
Main entry: Quercus marilandica, jack oak, blackjack, blackjack oak
Definition: a 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