Amistad National Recreation Area - Desert Plants

Amistad National Recreation Area by National Parks Service

Many people believe deserts are barren, sandy wastelands. Actually, deserts are second only to rain forests in the variety of plant and animal species that live there. Desert plants have adapted to the arid environment and are able to grow in very inhospitable habitats. They display a wide variety of shapes and sizes, and have amazing ways of tolerating extreme changes in temperature and rainfall. Spiny surfaces and waxy coatings provide insulation from the heat and minimize water loss through dry and hot seasons. Several cacti even utilize accordion-like pleating of their exterior in order to store water.

The barrel cactus will actually expand when it rains in order to take full advantage of the water present. When fully hydrated, a cactus can be 90-94% water, to last months or years until the next soaking rains. Unusual relationships between animals and plants have also arisen due to the harsh climate. An example is the yucca plant and pronuba moth, which have developed a symbiotic relationship. The yucca plant provides food and shelter for the moth and its offspring while the moth ensures fertilization of the plant. The Yucca plant produces hundreds of seeds and allows the larval stage of the moth to consume some of the seed in order to ensure the future generations of both the plant and moth. The blooming period of plants in western Texas is related both to rainfall and the season of the year. Some plants react almost immediately to passing showers.

The area around Amistad is famous for the blooms of the ceniza, or "purple sage," which blankets the hills in rolling waves of purple blooms after summer thunderstorms. Others plants bloom regularly in the spring or fall, or both. Rainfall in this area tends to be heaviest in early spring and early fall, so this double blooming period allows a second chance for plants to reproduce.