Besides the other descriptions I’ve already quoted, James Michener has more such in his book “Texas“, as his fictional character Ludwig Allerkamp sees it in the middle of the 19th century:
“[...] this central part of Texas consisted of five clearly defined strips, each a minor nation of its own.
Along the Gulf, [...] Texas was a swampy flatland inhabited by mosquitoes of enormous size and birds of great beauty. Summers were intolerably hot and amp, but the remainder of the year could be dazzling in its movement of wildlife and the brilliance of its long sunsets. People brave enough to live here tended to love the loneliness, the vast expanses of marshland and the interplay of sea and shore.
Inland came the treeless flats, enormous stretches of prairie populated by wild horses and unbranded cattle. Low shrubs dominated the sandy soil and a thousand acres represented a small field [...].
He [Ludwig Allerkamp] appreciated most the third strip, [...], that mysterious area in which the land began to form small hillocks, the streams wandered easily down twisting valleys and, most precious of all, trees began to appear, cedars, cypresses and four different kinds of oaks, including a small-leafed variety covered with some dead-looking substance of crepuscular character. When he asked aout the sickness which had attacked these small-leafed trees, he was told: ‘Those are live oaks, and that’s Spanish moss ‘ Very quickly he came to revere the live oak as one of the great boons of Texas.
[...] the fourth strip, one of the marvels of Texas, a sudden uprising of cliffs and rocky prominences called the Balcones, which stretched north to south for over a hundred miles, delineating the end of the prairies and the beginning of the hill country. Here trees began to show in great variety, flat plains disappeared and rivers ran through gorges. The Balcones had no great depth, east to west they wre rarely more than half a mile wide, but they formed a remarkable feature which could not be missed. “
James Michener, Texas (New York, 1985), pp. 601 f.