Habitats within Big Bend National Park support over 1300 plant taxa (about 1200 species). Hundreds of these species and varieties are showy, fragrant, or unique-looking enough to be generally categorized as “wildflowers”. In the Big Bend, there are usually two major flowering periods per year—spring and late summer/early fall. The spring flower season, because it depends largely on the amount and timing of winter precipitation, is less predictable than the summer/fall season, which is fueled by the dependable summer monsoon.
Many annual plants, like bluebonnets and some mustards, only bloom in early spring. The majority of the 46 cactus species in the park bloom in mid to late spring. Many of these cactus species produce very large, showy flowers in varying shades of yellow, red-orange, pink, and magenta. The yuccas, including the impressive giant dagger, usually flower February–April. Many shrubs and small trees, such as the fragrant yellow huisache in the southeast part of the park, and the bright purple, fruity-smelling Texas mountain laurel also bloom in March and April. Bright, fiery-red tubular flowers emerge at the ends of the spiny, whip-like branches of ocotillo by the first of April providing nectar and pollen for hummingbirds, bees, and butterflies. The spring flowering season frequently starts in late February along the Rio Grande and proceeds upslope to the foothills of the Chisos Mountains by late April.
The late summer flowering season is dominated by members of the sunflower family. These plants are sometimes called composites because the “flower” is actually a tightly clustered group of very small individual flowers. Most summer-flowering composites are yellow or white, with yellows being abundant in the Chisos Mountains. Several varieties of sage (genus Salvia) sport eye-catching red, blue, or purple flowers in the Chisos Mountains in summer. The high country wildflower show can last well into the fall, before the first freeze hits the mountains.
Another group of plants commonly called "desert sage" or cenizo grow in the mid to lower elevations of the park. These are not true sages (members of the mint family) but rather, are members of the figwort family. These hardy desert shrubs often explode in a profusion of blossoms (pale lavender, magenta, or deep purple) after significant summer rains.
Many plants are opportunistic, and will bloom whenever it is warm and wet enough, from February through November, and even sometimes in the middle of winter. Several yellow composites, like the forbs yerba raton, dogweed, paperflower, and the shrubby skeleton-leaf goldeneye bloom almost continuously in wet years. Many thorny acacia species will produce white to yellow blooms resourcefully throughout the warm months. The most common perennial mustard in the park, the deliciously fragrant bi-colored mustard, can bloom extensively in the spring and then again, though less spectacularly, in late summer.
Angiosperms (flowering plants), like those mentioned above, are the most numerous and diverse group of plants is the park, but dozens of gymnosperms (cone-bearing plants like pine and juniper), and non-seed producing plants (ferns), also grow here, especially in the cooler, wetter Chisos Mountains. Not all “flowering” plants produce stereotypical, colorful petal-bearing flowers. In fact, one of the most important and diverse families of flowering plants in the Big Bend (and the world), is the grass family. Grasses produce numerous small, reduced flowers in a wide array of flower arrangements, all well-adapted to wind pollination. Viewed up close with a hand lens or macro camera lens, these diminutive flowers can be quite beautiful when they produce flowering tillers in the rainy season.In the spring, late summer, and fall, you may be amazed at the abundance and variety of wildflowers. But regardless of when you visit, you are likely to find something in bloom. In the desert, lengthy dry spells are not uncommon, so there will be times when flowers are few and far between. Drought is a natural part of this environment, and the plants that live here are well adapted to these conditions. Please be respectful of the environment, and remember that all plants are protected within the national park.