Wherever it grows, it is a conspicuous object on the landscape and has been appropriately named "The Sentinel of the Desert."Its mammoth body is supported by a skeleton of wooden ribs, which are held in position by a mesh of tough fibers that is filled with a green pulp. Rows of thorns extend its entire length which are resinous and, if ignited, burn with a bright flame. They are sometimes set on fire and have been used by the Apaches for making signals. The cactus tree, like the eastern forest tree, is often found bored full of round, holes that are made by the Gila woodpecker. When the tree dies its pulp dries up and blows away and there remains standing only a spectral figure composed of white slats and fiber that looks ghostly in the distance.
Its fruit is delicious and has the flavor of the fig and strawberry combined. It is dislodged by the greedy birds which feed on it and by arrows shot from bows in the hands of the Indians. The natives esteem the fruit as a great delicacy, and use it both fresh and dried and in the form of a treacle or preserve.
The ocotillo, or mountain cactus, is a handsome shrub that grows in rocky soil upon the foothills and consists of a cluster of nearly straight poles of brittle wood covered with thorns and leaves. It blossoms during the early summer and each branch bears on its crest a bunch of bright crimson flowers.
If set in a row the plant makes an ornamental hedge and effective fence for turning stock. The seemingly dry sticks are thrust into yet drier ground where they take root and grow without water. Its bark is resinous and a fagot of dry sticks makes a torch that is equal to a pineknot.
The echinocactus, or bisnaga, is also called "The Well of the Desert." It has a large barrel-shaped body which is covered with long spikes that are curved like fishhooks. It is full of sap that is sometimes used to quench thirst. By cutting off the top and scooping out a hollow, the cup-shaped hole soon fills with a sap that is not exactly nectar but can be drunk in an emergency.
Men who have been in danger of perishing from thirst on the desert have sometimes been saved by this unique method of well digging.
Greasewood, or creasote bush as it is sometimes called on account of its pungent odor, grows freely on the desert, but has little or no value and cattle will not touch it. Like many other desert plants it is resinous and if thrown into the fire, the green leaves spit and sputter while they burn like hot grease in a frying pan.
The mesquite tree is peculiarly adapted to the desert and is the most valuable tree that grows in the southwest. As found growing on the dry mesas of Arizona, it is only a small bush, but on the moist land of a river bottom it becomes a large forest tree. Amesquite forest stands in the Santa Cruz valley south of Tucson that is a fair sample of its growth under favorable conditions.
Its wood is hard and fine grained and polishes beautifully. It is very durable and is valuable for lumber, fence posts and firewood. On the dry mesas it seems to go mostly to root that is out of all proportion to the size of the tree. The amount of firewood that is sometimes obtained by digging up the root of a small mesquite bush is astonishing.
It makes a handsome and ornamental shade tree, having graceful branches, feathery leaves and fragrant flowers, and could be cultivated to advantage for yard and park purposes.
Its principal value, however, lies in its seed pods, which grow in clusters and look like string beans. The mesquite bean furnishes a superior article of food and feeds about everything that either walks or flies on the desert. The Indians make meal of the seed and bake it into bread. Cattle that feed on the open range will leave good grass to browse on a mesquite bush. Even as carnivorous a creature as the coyote will make a full meal on a mess of mesquite beans and seem to be satisfied. The tree exudes a gum that is equal to the gum arabic of commerce.
The palo verde is a tree without leaves and is a true child of the desert. No matter how hot and dry the weather the palo verde is always green and flourishing. At a distance it resembles a weeping willow tree stripped of its leaves. Its numerous long, slender, drooping branches gracefully criss-cross and interlace in an intricate figure of filigree work. It has no commercial value, but if it could be successfully transplanted and transported it would make a desirable addition to green-house collections in the higher latitudes.
The romantic mistletoe that is world renowned for its magic influence in love affairs, grows to perfection in southern Arizona. There are several varieties of this parasitic plant that are very unlike in appearance. Each kind partakes more or less of the characteristics of the tree upon which it grows, but all have the glossy leaf and waxen berry.
