More than 500 species of grasses covered Texas when the Spanish and Anglo-Americans arrived. Although plowing and lack of soil conservation destroyed a considerable portion of this rich heritage, grassy pastureland still covers about two-thirds of the state. Bermuda grass is a favorite ground cover, especially an improved type called Coastal Bermuda, introduced after World War II. The prickly pear cactus is a mixed blessing: like the cedar and mesquite, it saps moisture and inhibits grass growth, but it does retain moisture in periods of drought and will survive the worst dry spells, so (with the spines burned off) it can be of great value to ranchers as cattle feed in difficult times. The bean of the mesquite also provides food for horses and cattle when they have little else to eat, and its wood is a favorite in barbecues and fireplaces.
Texas has more than 20 native trees, of which the catclaw, flowering mimosa, huisache, black persimmon, huajillo, and weeping juniper (unique to the Big Bend) are common only in Texas. Cottonwood grows along streams in almost every part of the state, while cypress inhabits the swamps. The flowering dogwood in East Texas draws tourists to that region every spring, and the largest bois d'arc trees in the US are grown in the Red River Valley. Probably the most popular shade tree is the American (white) elm, which, like the gum tree, has considerable commercial importance. The magnolia is treasured for its grace and beauty; no home of substance in southeastern Texas would have a lawn without one. Of the principal hardwoods, the white oak is the most commercially valuable, the post oak the most common, and the live oak the most desirable for shade; the pecan is the state tree. Pines grow in two areas about 600 mi (970 km) apart—deep East Texas and the trans-Pecos region. In southeast Texas stands the Big Thicket, a unique area originally covering more than 3 million acres (1.2 million ha) but now reduced to about one-tenth of that by lumbering. Gonzales County, in south-central Texas, is the home of palmettos, orchids, and other semitropical plants not found anywhere else in the state. Texas wild rice and several cactus species are classified as endangered throughout the state.
In 2003, 28 Texas plant species were listed as threatened or endangered, including ashy dogweed, black lace cactus, large-fruited sand-verbena, South Texas ambrosia, Terlingua creek cats-eye, Texas snowbells, Texas trailing phlox, and Texas wild-rice.
Possibly the rarest mammal in Texas is the red wolf, which inhabits the marshland between Houston and Beaumont, one of the most thickly settled areas of the state; owing to human encroachment and possible hybridization with coyotes, the red wolf is steadily disappearing despite efforts by naturalists throughout the United States to save it. On the other hand, Texans claim to have the largest number of white-tailed deer of any state in the Union, an estimated 3 million. Although the Hill Country is the white-tailed deer's natural habitat, the species has been transplanted successfully throughout the state.
Perhaps the most unusual mammal in Texas is the nine-banded armadillo. Originally confined to the Rio Grande border, the armadillo has gradually spread northward and eastward, crossing the Red River into Oklahoma and the Mississippi River into the Deep South. It accomplished these feats of transport by sucking in air until it becomes buoyant and then swimming across the water. The armadillo is likewise notable for always having its young in litters of identical quadruplets. The chief mammalian predators are the coyote, bobcat, and mountain lion.
Texas attracts more than 825 different kinds of birds, with bird life most abundant in the lower Rio Grande Valley and coastal plains. Argument continues as to whether Texas is the last home of the ivory-billed woodpecker, which lives in inaccessible swamps, preferably in cutover timber. Somewhat less rare is the pileated woodpecker, which also inhabits the forested lowlands. Other characteristic birds include the yellow-trimmed hooded warbler, which frequents the canebrakes and produces one of the most melodious songs of any Texas bird; the scissor-tailed flycatcher, known popularly as the scissor-tail; Attwater's greater prairie chicken, now declining because of inadequate protection from hunters and urbanization; the mockingbird, the state bird; and the roadrunner, also known as paisano and chaparral. Rare birds include the Mexican jacana, with a flesh comb and bright yellow-green wings; the white-throated swift, one of the world's fastest flyers; the Texas canyon wren, with a musical range of more than an octave; and the Colima warbler, which breeds only in the Chisos Mountains. In the Aransas National Wildlife Refuge, along the central Gulf coast, lives the whooping crane, which has long been on the endangered list. Controversy surrounds the golden eagle, protected by federal law but despised by ranchers for allegedly preying on lambs and other young livestock.
Texas has its fair share of reptiles, including more than 100 species of snake, 16 of them poisonous, notably the deadly Texas coral snake. There are 10 kinds of rattlesnake, and some parts of West Texas hold annual rattlesnake roundups. Disappearing with the onset of urbanization are the horned toad, a small iguana-like lizard; the vinegarroon, a stinging scorpion; and the tarantula, a large, black, hairy spider that is scary to behold but basically harmless.
In addition to providing protection for the animals on federal lists of threatened and endangered species, the state has its own wildlife protection programs. Among the animals classified as non-game (not hunted) and therefore given special consideration are the lesser yellow bat, spotted dolphin, reddish egret, whitetailed hawk, wood stork, Big Bend gecko, rock rattlesnake, Louisiana pine snake, white-lipped frog, giant toad, toothless blindcat, and blue sucker. In 2003, 63 animal species were listed as threatened or endangered in Texas (up from 43 in 1997), including the Mexican long-nosed bat, Louisiana black bear, bald eagle, ocelot, Mexican spotted owl, Texas blind salamander, Houston toad, black-capped vireo, two species of whale, and five species of turtle.
Texas has 15 National Wildlife Refuges, with a total of 302,731 acres (122,511 ha). The Texas Parks and Wildlife Department administers an additional 19 wildlife management areas.