The stems lie flat on the ground with their tips somewhat upturned, thus resembling huge caterpillars, head and body; they grow along on the ground, rooting from their lower surfaces, elongating at the tips, and dying back behind, which results in a slow forward movement of the whole plant. When this cactus meets with a log or stone the stem with its upraised tip gradually grows over this hindrance, up one side and down the other, and by the dying back of the rear end, in time passes over the obstruction. The stems, varying from three to nine feet in length and nearly as large as a man’s arm, are very spiny, with fifteen to twenty radial and central thorns of a dark brownish hue and dull tan, turning to grayish white with age, the tips translucent yellow. The flowers are bright yellow, the fruit delicious and relished by Indians and Mexicans both as a salad and as a preserve. Senita (_Cereus Schottii_) _Lower California, Sonora, and Southwestern Arizona_ [Illustration: SENITA, ZINA, OR SINA (Cereus Schottii)] The next growth to attract our notice is that called by botanists _Cereus Schottii_ or _Lophocereus Schottii_. It is named also for convenience Senita, Zina, and Sina. This is a remarkable cactus found in Sonora (a state of Northern Mexico), southwestern Arizona, and Lower California under the most arid conditions. It grows commonly in colonies and patches in the mountain cañons and there enjoys protection that the individual plants do not have. The young plants are equipped with silvery, short, stout spines, and the old ones with slender, long, flexible bristles, grayish or purplish gray, giving the appearance of old age—hence the common popular name of Senita. At a little distance these bristlelike thorns appear like fine purplish bands, from their symmetrically twisted spiral arrangement on the five- to twenty-foot yellow-green stems, which are supported by wooden cores or scalloped cylinders. Senita plants are very striking on the arid mountain slopes, along the foothills, and in protected valleys and cañons where the winter is warm and the summer hot, their dense branches often interlocking in huge clumps twenty feet across and twenty-five feet high. Their bristly stems resemble somewhat a squirrel’s tail or bottle brush, and in Mexico the plants are grown for fences which are unique and effective. The flowers are about an inch and a half long and as wide, shaped like a bell, with very lovely cream-white and pale pink petals shading into deep pink at the tips. The fruit is a greenish brown changing to dull red when mature, and globose. The blossoms and fruit of this species are rather small for the Cereus; the flowers open in the evening and close in the morning, and while delicate are not at all showy. Prohibition Cactus (_Cereus Emoryi_) _Lower California, Northern Mexico, and Southwestern California_