Part 6

Lupinus excubitus Pea Family

35. Smoke-thorn

Better known as “smoketree,” this silvery-gray, seemingly leafless shrub grows in and along sandy washes below 1,500 feet, throughout the Mojave-Colorado Desert. At a distance it resembles a plume of smoke rising from a campfire. Its small but violet to indigo flowers cover it with a gorgeous blue blanket in May, making it one of the really handsome desert shrubs. It requires ample supplies of water, hence is restricted to washes that carry runoff from both winter rains and summer downpours. The seeds sprout readily, and the seedlings with their well-formed leaves look very unlike their parents. Few seedlings survive the hazards of drought or being smothered by sand carried down the washes by flash floods following cloudbursts.

Dalea spinosa Pea Family

36. Dalea

Noted for its royal purple flowers, this low shrub, less than 3 feet high with peculiar zig-zag branches, blossoms from April to June. In common with other daleas (day-LEE-ahs) it is usually called “indigobush” or “peabush.” It is normally found below 3,000 feet in desert mountain ranges from southern Utah through Arizona and southeastern California. There are many species of dalea in the desert, all characterized by deep blue to indigo and rose-violet flowers, which attract attention by their beauty. Indians used the extract from twigs for dyeing basketry.

Dalea fremontii Pea Family

37. Tesota

Thriving only in a frost-free climate, this is among the largest and most beautiful of desert evergreen trees. It is usually found along sandy washes, mingling with mesquites and paloverdes. It is particularly susceptible to mistletoe infestation, which has killed or weakened many fine trees. Blossoming in May and June, the trees are sometimes laden with lavender, wisteria-like flowers. The wood is extremely hard and heavy, hence the tree is locally known as “ironwood,” or palo-de-hierro, in Mexico. Indians ate the seeds and used the wood for tool handles and arrow-points. Its long-burning qualities made it especially desirable for fuel. As a result, many of the trees have been cut, making it one of the species threatened with extinction.

Olneya tesota Pea Family

38. Woolly loco

Many species of “locoweed” ranging in color from deep purple to creamy white are found throughout the desert at nearly all elevations. They sometimes create extensive mass displays but are more commonly found mixed with other flowers. Species with bladder-like pods are called “rattleweed.” Loco in Spanish means “crazy” and refers to the fact that a number of species of astragalus contain selenium, which causes a serious disease among livestock, especially horses, that eat it and as a result “act crazy.”

Astragalus mollissimus Pea Family

39. Heron-bill

Also called “alfileria,” this species and its close relative, Texas filaree (Erodium texanum) are both early blossoming annuals, often widespread on plains and mesas, February to May. The flowers, although abundant, are small and so hidden in low-growing foliage that they rarely create a mass display. Texas filaree is native to North America, but alfileria is thought to have come from Europe with the Spaniards, and is now naturalized throughout the Southwest. Corkscrew-like appendages of the fruits are tightly twisted when dry, but untwist when moist, literally screwing the sharp-pointed fruits into the soil. Both species are excellent spring forage for livestock.

Erodium cicutarium Geranium Family

40. Creosotebush

Often erroneously called “greasewood,” creosotebush is generally recognized as the most adaptable of all desert plants, and a definite indicator of the Lower Sonoran Life Zone. The shrubs cover thousands of square miles, often in pure stands, and flower throughout much of the year, but most profusely in April and May. Fuzzy white, globular fruits are almost as spectacular as the flowers. The plant can endure long periods of drought. Following rains its foliage gives off a musty, resinous odor, suggestive of creosote, stimulating the Mexican name hediondilla (little stinker). In Mexico the plant is considered to have medicinal values and many uses. The Pima Indians boiled the leaves, using the decoction as an emetic and to poultice sores. They used the lac, found as an incrustation on the branches, to cement arrow-points and to mend pottery.

Larrea tridentata Caltrop Family

41. Arizona-poppy

Often abundant on road shoulders and in low spots where rainwater from hot-weather showers provides adequate moisture, “caltrop” or “summerpoppy,” with large blossoms and attractive compound leaves, decorates the desert when other flowers are noticeable by their absence. The long, weak stems, usually prostrate, give the plants a vine-like appearance, but when growing under shrubs they extend upward so that the shrub is mistakenly thought to be blooming. Superficially resembling the springtime goldpoppy, Arizona-poppy has five rather than four petals, and may be found in bloom as late as October.

Kallstroemia grandiflora Caltrop Family

42. Desert-mallow

Ranging in size from delicate 6-inch annuals to coarse, woody perennials 4 feet high, the globemallows vary in color from creamy white to pink, rose, peach, and lavender. Desert-mallows flaunt their graceful, blossom-covered stems along roadsides or on the banks of sandy washes. Because some people are allergic to them, globemallows are called “sore-eye poppies” in parts of southern Arizona, and in Lower California are known as plantas muy malas (very bad plants).

Sphaeralcea ambigua Mallow Family

43. Five-stamen tamarisk

Sometimes confused with tamarack because of the similarity of names, five-stamen tamarisk, locally called “salt-cedar,” is one of several small tree species from southeastern Europe and western Asia which have become naturalized in North America. “Salt-cedar” often forms dense thickets on alkaline soils along stream and reservoir banks at elevations below 5,000 feet. Flowers, which vary in hue from deep pink to white, cover the trees with graceful plumes of color from March to August. Although valuable in retarding soil erosion, tamarisk requires large quantities of water, an especially undesirable characteristic in the arid Southwest.

Tamarix pentandra Tamarix Family