Another friend to the desert wanderer is the _chlorogalum pomeridianum_, or soap plant. This grows from two to five feet high and has a bulbous root two or more inches in thickness which is an excellent substitute for soap--hence its name. The leaves are from one to two and one half feet in length, and from an inch to an inch and a half in thickness. The plant flowers in July and August, the blossoms opening in the afternoon only. The bulb of the plant lies deep in the earth and has the power of storing moisture, in time of rain, for the long, dry months which follow. As previously stated, the numbers of the cactus family to be found in various portions of the desert are almost innumerable. In a three-days' journey through the southern desert, taken early in May, the writer noted forty-two different varieties of cacti in blossom. These ranged from the delicate bloom of tiny plants to the gorgeous blossoms of the giant species, thirty, forty, and even fifty feet in height. [Illustration: "THE WELL OF THE DESERT" From photograph by C. C. Pierce & Co.] It was a most memorable trip. At no other season of the year does the desert present so gay an appearance as in May and early June. Blossoms, white, pink, yellow, purple, and scarlet, are to be seen on all sides, till one loses the idea that he is in the desert and almost dreams that he is in some wonderful garden. But there are no sparkling fountains and grassy lawns to complete the illusion; only the thorny shrubs with their vivid blossoms and the scorching sands, the dust, the thirst, and the cloudless sky above. A very common species of cactus is the nopal or prickly-pear, the fruit of which is known as the tuna, and which is much prized both by Indians and by Mexicans. A welcome plant to the desert traveler is the bisnaga, or "well of the desert." This is a cylindrical-shaped green plant thickly covered with sharp spines. By cutting out the center of the plant, a bowl is formed which quickly fills with water of an excellent quality, affording a palatable drink to the thirsty traveler. Many a life has been saved by these plants, and there have been a number of instances recorded where travelers, ignorant of the properties of the plant, have died of thirst in the midst of them. Another cactus found in the southern desert is the grape cactus, which bears in clusters fruit resembling the tuna. The fruit is green without and purple within, is juicy, melting, and luscious. A very common and ungainly plant is the ocotilla, growing clusters of straight poles from ten to fifteen feet in height, which are covered with spines. The poles terminate in long spikes of beautiful scarlet blossoms. The maguey or mescal, sometimes misnamed the century plant, is common along the foothills bordering the desert. It is from this plant that the Mexicans and Indians distil the fiercely intoxicating drink known as mescal, which contains a large percentage of alcohol of a villainous quality.