'jack oak' definitions:

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 [syn: blackjack oak, blackjack, jack oak, Quercus marilandica]

Small to medium deciduous oak of east central North America; leaves have sharply pointed lobes [syn: jack oak, northern pin oak, Quercus ellipsoidalis]