When we think of the trees we have in the Hill Country (other than cedar) most of us think of the oaks. And while the live oak is the most common, we have several other species of oaks that add variety to our landscape. Here are the main ones:
Blackjack oaks (Quercus marilandica) are one of two species (the other being Spanish oaks) in the Hill Country that belong to the Red Oak family. All the other oaks are classified as White Oaks, except that live oaks are sometimes considered a class by themselves. Blackjack oaks tend to have darker bark than most other trees in the area and the leaves are thin, shiny, smooth and tend to have a shape like a duck’s foot. At the tip of the leaf where the “duck’s toenails” would be you can usually see a very small hair-like point sticking out.
Chinquapin oaks, also spelled chinkapin, (Quercus muhlenbergii) are large trees usually found in the deeper soils along creeks and streams. They have oblong leaves 3” to 5” long with scalloped edges. They can be successfully grown in a moderate amount of soil even quite removed from any creeks.
Lacey oaks (Quercus laceyi) were first described by an Englishman, Howard Lacey, who owned a ranch in the Turtle Creek area south of Kerrville in the late 1800s. They are also called “blue oaks” as the color of their leaves tends to be somewhat blue-green, which means they can be picked out from other trees at a distance. They are usually medium-size trees that often grow in rocky areas along the edge of hilltops, but they seem to be able to grow almost anywhere.
Live oaks, which make up the majority of all oak trees in the Hill Country, are predominately plateau live oaks (Quercus fusiformis) which are a slight variation from the live oak (Quercus virginiana) that grows from the Texas coast east to the Atlantic Ocean. They are usually referred to as being evergreen, since they keep their green leaves throughout the winter. But they are not strictly evergreen because they do lose their leaves beginning in March or April and they immediately begin growing new leaves. This process, called “leaf exchange”, may take until May to complete. Live oaks can be found growing almost anywhere in the Hill Country.
Post oaks (Quercus stellata) tend to have the lightest-colored bark of all the other trees. They also tend to have very straight trunks (i.e. like a post). Their leaves are often described as cross-shaped with large bulges on either side of the leaf near the top. The leaves also have a somewhat rough feel when rubbed between the fingers and lack the “points” found on blackjack oaks, with which they are sometimes confused.
Shin oaks (Quercus sinuata) are also known as White shin oaks and Bigelow oaks. They tend to be the smallest oak species in this area, usually no more than 12-15’ tall. They have a fairly light-colored bark that looks shaggy as though pieces of the bark are flaking off. These trees frequently grow close together in groups and it is common for them to produce many root sprouts near the base of the trees, although if you have many deer, you may never see the sprouts.
Spanish oaks (Quercus buckleyi), also known as Texas red oaks, have deeply-lobed leaves (deep indentations between fingers with points) and tend to give the most fall color of all the oaks in the Hill Country. They also green up early in the spring with very light-colored leaves which contrasts nicely with the deep green of the cedars. Spanish oak bark frequently, but not always, has whitish patches of lichen on it.
Spanish oaks are very closely related to Shumard oaks which are found east and north of the Hill Country, but the latter do not do as well here as the native Spanish oaks.
Some might include Bur oaks in the above list, but they are only common natively a little further east and north of us.
All oaks produce acorns, which are an important seasonal food source for deer, turkey and squirrels. Red oak acorns take two seasons to mature while white oak acorns mature in one season.
Photos of the leaves of these oaks as well as other Hill Country trees can be seen on the photos page of my website, www.hillcountrynaturalist.org.
Until next time…