Flowering in May and June and common throughout southwestern New Mexico, southern Arizona, and northern Mexico, the walkingstick cholla is best known because of its persistent clusters of yellow fruits. These remain throughout the winter, giving persons the first-glance impression that the large shrubby cactus, sometimes 8 feet high, is in bloom. The fruits are eaten by cattle. This species is typical of desert grasslands and is most abundant in the open country below the edge of the oak belt in desert mountains. Stems of the dead plants leave a hollow cylinder of attractive wooden meshes when the soft tissues decay, and are favored for making canes, as the stem is long and straight, hence the name walkingstick cholla.
Also called “sun-drops,” these plants are particularly welcome because they bloom early in the springtime. Many species of evening-primrose are large flowered, abundant along roadsides and sandy flats, and notably fragrant. White-flowered species are more common, but there are several with yellow flowers. Blossoms open at night and begin to wilt, turning pink during the following day. These are among the handsomest of desert plants and during favorable years make a spectacular spring display, sometimes growing with goldpoppies and sandverbenas to produce a riot of color.
_Oenothera trichocalyx_ Evening-primrose Family
Common to all of the deserts crossed by the boundary between the United States and Mexico, ocotillo (oh-koh-TEE-yoh) is a spectacular shrub, its many long, stiff, green-barked and thorn-guarded stems bearing at their tips clusters of bright red flowers from April to June. Following rains, the stems cover themselves with clusters of bright green leaves. When drought comes these leaves are shed, to be renewed again after another rain. This procedure may be repeated half a dozen times in one year. Cahuilla Indians eat both flowers and seeds, and make a beverage by soaking the blossoms in water. When planted as hedgerows the thorny wands make an impenetrable fence.
Also known as “wild morning glory,” this naturalized perennial has become a serious agricultural pest throughout the Southwest. In California it is considered the State’s worst weed. Once established, its deep root system spreads widely, sending up shoots that grow rapidly with climbing, vine-like stems and morning glory-like white to pink flowers that bloom from May to July. In the desert it is usually found on road shoulders, where it makes an attractive display. The name _convolvulus_ comes from the Latin and means “to entwine.” A blood-clotting substance has been found in this plant.