The Oaks Of Texas

White oaks

Acorns annual with inside-of-cup smooth. Bark white to gray, soft and scaley (sometimes black, hard and furrowed as in the “Live Oak”); leaves usually more or less rounded, perhaps sharp pointed teeth but not bristle tipped.

Black oaks

Acorns biennial (pollinated one year and fertilized the following year), annual for Emory, Silverleaf annual or sometimes biennial; acorn cup fuzzy on inside. Bark black, hard and furrowed; leaves usually toothed and bristle tipped (aristate).

Heights

In their native environment, the Texas oaks can range in heights from less than 3 ft to well over 100. Most lot sizes (for homes) preclude the use of the larger oaks. Smaller trees are needed and can readily be chosen from the following oaks:

”Live oaks” (Persistent Leaved)

There are 19 persistent-leaved species of oaks in Texas. To call them “evergreen” is not entirely correct because they usually drop all their leaves at one time. However, if temperatures permit, they do hold their leaves overwinter. One of the persistent-leaved oaks that occurs along the coast near Victoria is a rhizomatous live oak that Muller (12) considers to be a juvenile form of Q. virginiana. However, this population along with those in Calhoun County, may be Q. minima × Q. virginiana while south of Corpus Christi it might be Q. oleolde × Q. fusiformis (15). These rhizomatous oaks fruit heavily at less than 3 ft. and remain in this form idefinitely.

”Grassland oaks”

With the exception of the eastern Piney Woods and the basin and range of the Trans-Pecos, Texas is a prairie state. Most of the Trans-Pecos, while not true prairie, is still grassland and the oakhickory and pineland of eastern Texas contain openings of grassland.

The East and West Cross Timbers are postclimax oak savanna of post and blackjack oak (2). A narrow belt of tailgrass prairie extends from the Red River to the Gulf Coast and contain scattered stands of bur oak. Bur oak in the midwest is postclimax (18) in much the same manner as the post oak-black jack oak in the East and West Cross Timbers and the Post Oak Savanna.

Of greater interest are those oaks of the Gulf Coast, the Edwards Plateau and the oaks along and to the west of the 100th meridian, that are white oaks, more or less dwarf and rhizomatous. They occupy grasslands and appear to have evolved with the fires of the prairies (15).

Oaks for fall foliage color

Most oaks, except for the persistent-leaved species, exhibit some color in the fall. An exception is Mexican Blue Oak, a live or persistantleaved oak that still gives color in the fall. The oaks listed below exhibit fall foliage color in most years.

Oaks for different soils

Fifteen Texas oaks of unusual landscape merit

• Quercus alba (White oak) - Large tree of acid soils, excellent fall foliage.

• Q. emoryi (Emory oak) - Medium tree of igneous soils in the mountains and valleys of the west, good persistent foliage.

• Q. fusiformis (Escarpment live oak) -Motte forming medium oak of alkaline soils, persistent foliage.

• Q. glaucpides (Lacey oak) - Medium oak, alkaline soils, blue-green leaves.

• Q. laurifolia (Laurel oak) - Large oak, acid soils, persistent foliage.

• Q. macrocarpa (Bur oak) - Massive oak of the prairies, will grow in almost any soil.

• Q. mohriana (Mohr oak) - Small oak of the hard limestone soils of western Texas, persistent foiliage.

• Q. muehlenbergii (Chinkapin oak) -Large oak of alkaline soils usually in river bottoms.

• Q. oblongifolia (Mexican blue oak) - Small oak, persistent foliage, blue-green to mauve leaves in winter.

• Q. pungens var. vaseyana (Vasey oak) -Small oak, with persistent, glossy foliage, usually in alkaline soils.

• Q. shumardii (Shumard red oak) - Large oak of bottomlands, excellent fall foliage.

• Q. sinuata var. breviloba (Bigelow oak) -Small oak with multiple stems on hard limestone, excellent flaking bark.

• Q. texana (Texas red oak) - Medium oak of dry limestone soils, magnificent fall foliage.

• Q. turbinella (Shrub live oak) - Dwarf oak of the Franklin Mountains, persistent silvery- gray foliage.

• Q. virginiana (Coast live oak) - The “Live oak”, large tree of coastal areas east of Brazos River , persistent foliage.