Several trees of the oak genus Quercus grow in Texas, with the majority of them existing in the eastern portion of this huge state where the soil is better suited to their needs. Among them are species such as the chinkapin oak, black oak, Shumard oak, post oak, bur oak and blackjack oak. Each of these oak trees has differences in their leaves, acorns, bark and size. Identify these Texas trees by studying their most prominent features to decide which type they are.
Browse through the range maps of Texas oak species online or look in a field guide to learn about in what parts of the Lone Star State each oak species grows. This activity will help you eliminate certain oaks from certain portions of Texas. For instance, if you are in the middle of Texas and trying to determine if an oak is a white oak or a Shumard oak, a look at the maps will show you white oak only grows in far eastern Texas, while Shumard oak's range extends well into the central part of the state.
Approximate the height of the oak tree and use this information in your analysis. Many Texas oaks grow in the 70 to 80 foot range, so estimating the height will not help you much. Nevertheless, others, such as blackjack oak, only grow to between 20 and 30 feet, which will help you immensely as you try to identify it.
Examine the size of the leaves of the oak trees you encounter in Texas. Take careful measurements of the length and width of several leaves from each tree. This data is extremely vital to your identification. You can rapidly identify the oaks like bur oak, with leaves a foot long and 6 inches wide, by the size of their leaves.
Study the shape of the Texas oak leaves. This again is one of the most important clues as you try to discern one oak from another in Texas. For example, swamp chestnut oak leaves resemble small kites with their shape, while blackjack oak leaves, with their three very shallow lobes on the end, look like the silhouette of a plump pear. Each Texas oak, like the oaks across the United States, have differences in the shapes of their leaves that will aid you in identifying the particular species.
Pick some of the acorns from these oak trees and use them to make an identification of the tree. Each oak tree has acorns of different shapes, lengths and with a unique cap. Some, like bluejack oak, have acorns of different sizes and shapes on the same tree, while others, like white oak, have uniform acorns, about an inch long with a warty cap that looks like a miniature bowl attached to it.
Scrutinize the bark of the oak trees and use such features as their texture and color to help identify the species. Black oak gets its name from the nearly black bark on the mature trees. White oak and post oak have gray bark that exists on the tree in scaly plates. Water oak possesses mottled black-gray bark that has distinct scaly ridges throughout. Complete your recognition of a Texas oak through the type of bark covering the tree.