Simmondsia chinensis

(Link) Schneid.

Jojoba Family Simmondsiaceae

The Spanish common name for this desert shrub is pronounced ho-HO-ba. With its dense canopy of evergreen leaves, jojoba may seem unfit for survival in the desert, but is extremely drought resistant. The leaves contain a high percentage of dry matter, which makes them rigid and therefore resistant to wilting. All are oriented vertically, so they intercept sunlight only early in the morning and late in the afternoon. By restricting photosynthesis to the relatively cool hours of the day, the plants conserve water.

Because they contain a compound related to cyanide, jojoba seeds, eaten in large quantity, are toxic to mammals, with the exception of the Bailey's pocket mouse, which has evolved a detoxification mechanism that renders the seeds harmless. In collecting and storing the seeds, Bailey's pocket mice act as jojoba gardeners, since the seeds that aren't eaten may germinate eventually, often as dense clusters of seedlings.

Ground jojoba seeds have long been used by Indians for shampoo and medicine. These days, the seed oil (actually a liquid wax) is considered a valuable substitute for oil from the endangered sperm whale. A variety of shampoos, cosmetics, soaps, lubricants, and pharmaceuticals contain jojoba oil. The demand is great enough that jojoba plantations have sprung up in western Arizona and southeastern California, typically in broad, silty valleys where planting and harvesting can be readily mechanized. In the wild, jojoba grows on rocky canyon slopes and along gravelly washes in southern California and Arizona.

Arizona grape

Engelm. Vitaceae

This scrambling or sprawling vine is sometimes called canyon grape because it grows in well-watered canyons from southern Nevada and Utah through Arizona and New Mexico into western Texas. Like the riparian trees with which it often grows — sycamore, velvet ash, cottonwood, willow—Arizona grape is hardly a desert plant. It requires deep and thorough irrigation and is never found far from permanent water.

The tendrils are weak; even so, the twining, woody stems often clamber into the upper branches of large trees. Arizona grape sometimes kills shrubs and small trees by shading them so thoroughly that their leaves cannot catch the sun to photosynthesize.

Appearing from April to June, the inconspicuous flowers are extraordinarily sweet-scented and attract large numbers of bees and other insects. The tasty, blackish-blue berries, which ripen by autumn, make excellent jelly and juice. Birds usually manage to strip the vines of fruit well before would-be jelly makers arrive.

A close relative, desert grape (Vitis girardiana Munson), grows in canyons at the edge of the Mojave Desert in southern California. It has cobwebby leaves and long, branched tendrils.

Desert fan palm

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