Two faces of Texas: along the Devils River, wetland meets desert, and eastern sycamore thrives in sight of Christmas cactus

The rocky Edwards Plateau--called the Hill Country by Texans--extends from Austin and San Antonio westward about 230 miles, where it merges with the Chihuahuan Desert. On its western margins, the plateau is semiarid; permanent rivers and streams are scarce. One that does flow year-round is the Devils River. Snaking southward for about a fifty miles, it enters the International Amistad Reservoir, created by the damming of the Rio Grande. Fed by numerous springs, the Devils River disappears underground for some stretches, only to reappear downstream. In several areas along the waterway, springs support a rich wetland flora, yet on dry terraces only fifteen feet above the wetlands grow plants of the desert: lechuguilla, ocotillo, San Angelo yucca, and Turk's head.

Two places to sample both habitats are the Devils River State Natural Area and, adjacent to it, the Nature Conservancy's Dolan Fails Preserve. The state natural area covers thirty-one square miles and is served by a hike-and-bike loop trail. It is open for primitive camping as well as for day use; entrance fees and other regulations apply. Permission from the Nature Conservancy is required to visit Dolan Falls Preserve, which is open periodically for scheduled Conservancy field trips and volunteer workdays [see contact information on opposite page].

The centerpiece of the Conservancy's eight-square-mile preserve is Dolan Falls, just downstream on the Devils River from its confluence with Dolan Creek. At the falls, the river drops eight feet over rocky ledges, creating a constant spray of water. Along the western side of Dolan Falls is a scenic, shaded woodland, home to a species of small tree called Texas plume or Anacacho orchid tree. It is a member of the genus Bauhinia, which occurs throughout the tropics but rarely this far north. Bauhinia leaves are divided from the tip to near the stem, forming two lobes. Texas plume bears large, pink blossoms in early April [see photograph at left].

One of the prettiest shrubs that grow along the bed of Dolan Creek and elsewhere in both the state natural area and the preserve is Texas snowbell. On the federal endangered list, the species is known only from a few localities in southwestern Texas. In late April and early May the shrubs are covered with clusters of nearly inch-long white flowers. Each flower has five narrow petals, which spring above a circular leaf whose underside is covered with silver hairs.

Native Americans frequented this area long before the first settler established a ranch here, in 1883. On the basis of rock-shelters, pictographs, and other finds, the Texas Archeological Society has identified nearly 250 Native American sites in the state natural area and the preserve; the earliest ones date from about 8,600 years ago. Historically recorded groups include Apaches, Comanches, Kickapoos, and Kiowas. At least one battle between the U.S. Cavalry and the Comanches took place on the bluffs overlooking the Devils River.

The Devils River lies along a migration route for birds and butterflies. Among the birds that nest in and around the state natural area and the preserve is the black-capped vireo, which spends the winter on the west coast of Mexico. It, too, is on the federal list of endangered species. Other breeding birds include Bell's vireo, the black-throated sparrow, the elf owl, the hooded oriole, the tropical parula, the red-shouldered hawk, the summer tanager, the white-eyed vireo, the yellow-breasted chat, and the zone-tailed hawk.

Other animals of note here are the Texas horned lizard and the Texas tortoise. In addition, several rare fishes live in the springs and the river, including the Devils River minnow, federally listed as threatened.

HABITATS

Wetlands Eastern sycamore often grows as tall as sixty feet, providing dense shade for plants such as American germander, bristly greenbrier, Carolina vetch, common boneset, giant goldenrod, scouring rush, and wild mint, all species common east of the Mississippi River. Mexican ash and the shrubby hoptree often occur with the sycamore. Southern maidenhair often hangs over the mouth of the springs, and watercress is common in the clear spring water.

Other wetland plants that occur along and in the shallow water of the river include American speedwell, American water-willow, California loosestrife, common buttonbush, common monkey-flower, Jamaica swamp saw grass, manyflower marshpennywort, narrowleaf blue-eyed grass, neckweed, switch grass, white star sedge, and several species of spikerush. Submerged in shallow water are entanglements of coon's tail, a common aquatic plant.

Woodlands In addition to Texas plume, mescal bean, or Texas mountain laurel, offers cooling shade, and its deep blue flowers are pretty in bloom. Other woody plants include fragrant sumac, evergreen sumac, little walnut, Mexican buckeye, Texas persimmon, Texas snowbell, and western white honeysuckle.

Dry mesas Gnarly shrubs and cacti are prominent members of the dry mesa flora, which includes allthorn, bear grass, Christmas cactus, desert myrtle croton, guayacan, javelin bush, lechuguilla, ocotillo, San Angelo yucca, Texas barometer bush (ceniza), Texas sotol, and Turk's head.