Northern Red Oak
The northern red oak is the namesake oak species of the red oak group. Often simply called red oak, it can grow very large and is found across the eastern US. Some trees drop acorns earlier than other oaks, making it a destination food source for deer in the early season.
Eastern US and southeastern Canada. Not as common in the Deep South.
Uplands and bottomlands, but usually not in very wet or dry locations.
Southern Red Oak - leaves of the northern red oak have shallower sinuses, and lack the rusty underside of southern red oak leaves. Acorns of the southern red oak are much smaller. Mature bark of southern red oak does not have the silvery "ski tracks" of northern red oak.
Scarlet Oak - Bark is very similar, often identical. However, the bark of scarlet oak is usually rougher or more blocky near the base of the tree. Acorns of scarlet oak have larger caps covering up to 1/2 of the acorn, while caps of northern red oak acorns only cover about 1/4. Leaves of scarlet oak have deep sinuses, often nearly reaching the midvein, while those of northern red oak are shallower, only reaching about half way to the midvein.
Black Oak - bark of mature black oak trees is rougher and usually more solid dark gray to black, and lacks the silvery plates or "ski tracks" of northern red oak. Leaves of black oak have some amount of pubescence on the undersides, while northern red oak leaves are smooth. Northern red oak leaves often have a bluish-green color, unlike black oak.
Shumard Oak - Acorns can be similar between the two species. Leaves of shumard oak have deep sinuses, and undersides of shumard oak leaves have characteristic tufts of brown hairs between the midvein and side veins. Bark of shumard oak is also typically smoother and more uniform gray in color.