- blackjack oak, blackjack, jack oak, Quercus marilandica - a common scrubby deciduous tree of central and southeastern United States having dark bark and broad 3-lobed (club-shaped) leaves; tends to form dense thickets
--1 is a kind of scrub oak
- jack oak, northern pin oak, Quercus ellipsoidalis - small to medium deciduous oak of east central North America; leaves have sharply pointed lobes
--2 is a kind of oak, oak tree