Desert plants of the American Southwest are rugged survivors which must withstand a great range of temperatures and get by on very little moisture. These plants are very well adapted to desert micro-climates and long term local weather patterns. Many of them are also surprisingly beautiful, with bright, but delicate blossoms, or rosettes of silvery leaves. Representatives of many species are found over vast areas of the Southwest in similar climatic zones.
Perhaps the most celebrated plants of the southwestern deserts are the many species of cacti. While some species, like the Saguaro, are found over a relatively limited range, others like the many varieties of cholla and prickly pear, grow over most of the Southwest. Other succulents, including many types of agave, are also widespread. Desert marigold grows in lower elevations, but can survive in elevations up to 5,000 feet. This low-growing, thread-leaved plant responds to seasonal rains with a profusion of bright yellow flowers from spring through late fall.
Many low-growing annuals and short-lived perennial plants grow in desert grasslands across the Southwest. Among them are many varieties of penstemons, including bush penstemon, pineleaf penstemon and desert penstemon. Winecups is another herbaceous perennial with showy blossoms, which is frequently found growing in desert grasslands.
Broom dalea, also called purple sage, is a common plant of dry shrub lands with sandy soil, where it may cover many square miles. It produces tiny, brilliant purple flowers in late summer, and its seeds are relished by native quail and other birds. Apache plume is another widespread shrub found in the southwestern desert. It is easily identified by its copious feathery pink seed heads, which seem to glow in the light of late afternoon or morning. Curl leaf mountain mahogany is a tall, upright shrub, with dark green leaves and gray bark, found along mid-elevation arroyos or dry stream beds. The leaves of this handsome shrub have a pleasant, spicy fragrance.
The Fremont cottonwood is one of the Southwest’s only large native canopy trees. These fast-growing, short-living trees line watercourses throughout the southwestern desert, providing critical habitat for raptors and migrating waterfowl. Their heart-shaped leaves turn a clear, golden yellow in fall. The Arizona sycamore is a tall, deciduous tree with attractive exfoliating bark, found in moist desert canyons. Its large leaves provide precious shade for other plants and animals. A common shrub found in wetter areas of the southwestern desert is the golden currant. It grows in canyons or near water bodies in the partial shade provided by tall trees, like ponderosa pines or cottonwoods.
Open forests of pinyon pine stretch for hundreds of miles across the Southwest, over dry rocky soils, at elevations above 5,000 feet. These pines are long-lived, medium-sized trees, which support many other plant and animal species by providing shade, shelter and forage. One-seed juniper is ubiquitous in the Southwest at elevations from 5,000 to 7,000 feet. It is commonly found interspersed with pinyon pine, especially at the higher parts of its range.