Notice whether the leaves are lobed or not lobed. Most oak trees have lobed leaves, but a few do not, such as the chestnut oak (Q. prinus), Chinquapin (Q. muehlenbergii), shingle (Q. imbricaria), swamp white (Q. bicolor), water (Q. nigra), willow (Q. phellos) and live (Q. virginiana) oak trees.
Determine the oak tree species by studying non-lobed leaves for "teeth" around the leaf edges. The chestnut and swamp white oaks have rounded teeth on their leaf edges, while the Chinquapin has coarse, deep teeth. The water and live oak leaves have smooth margins with no teeth.
Study the lobes on lobed oak tree leaves to identify the species, particularly whether the lobes are deep or shallow. The black (Q. velutina), blackjack (Q. marilandica) and red (Q. rubra) oak trees have leaves that are shallowly lobed. The bur, pin (Q. palustris), scarlet (Q. coccinea), Shumard (Q. shumardii) and Southern red (Q. falcata) oaks have deeply lobed leaves.
Notice whether the leaf lobes are broad or narrow. The black oak and scarlet oak leaves have lobes that broad toward the tips. The overcup oak (Q. lyrata) has rounded lobe tips and the red oak has lobes that narrow at the tips. The Southern red oak has narrow middle lobes, while the Shumard oak does not. The pin oak has broad middle lobes and narrower side lobes.
Study the lobes at the ends of the leaves. The bur oak (Q. macrocarpa) and overcup oak trees have end lobes that are larger than the others, the post oak's (Q. stellata) three end lobes are smaller than the others, and the white oak (Q. alba) has small end lobes that are similar to the others.
Take note of whether the lobes have bristle tips, which are tiny spines that protrude from the leaf edges. The black, pin, red, scarlet, Shumard and Southern red oaks all have bristle tips on their leaf lobes, while the other oaks do not. The blackjack oak has some lobes with bristle tips and some without them.
Study the leaf size to identify the oak species. The willow and live oaks have the smallest leaves, which are 2- to 5-inches long. The overcup oak's leaves are oblong and 6- to 8-inches long, the bur oak's leaves are 6- to 12-inches wide, and the Shumard oak has even larger leaves.
Look at the changing color of the leaves in fall to determine the oak-tree type. The sawtooth oak (Q. acutissima) has dark-green leaves that turn bright-yellow in autumn, while the live oak's leaves are evergreen. The white oak's leaves turn from red to pink to gray in spring, dark-green to slightly bluish-green in summer and brown to deep red to burgundy in fall. The chestnut oak's leaves turn orange-yellow to yellowish-brown, the Chinquapin oak's leaves turn yellow-orange to orangish-brown, the Northern red oak's leaves turn red in fall, the overcup oak has rich yellow-brown fall colors, the pin oak's leaves turn russet, bronze or reddish, the scarlet oak's leaves change to scarlet-burgundy, the Shumard oak's and water oak's fall leaves are yellow to orange to reddish, and the willow oak's leaves turn yellow, yellowish-brown and russet in the fall.