They can be grown indoors generally in the north and south temperate zones between the 34° and 54° parallels, north and south, where the temperatures reach as low as twenty to thirty degrees below zero. This includes the northern two-thirds of the United States, the lower half of the Dominion of Canada, Great Britain, Ireland, France, Germany, Austria, the northern half of the Chinese Republic, Japan, and the southern part of South America.
The Cereus Group or Torch Flower Cacti (Cereus)
How to identify and how they grow
Many species of this group can be identified by the beautiful candelabralike branching of the plants. They are trees, shrubs, or climbers, and grow erect or spread out, the tallest and largest trees or plants of the cactus family. They are the “torch flower” cacti, are tropical or subtropical, the stems growing single or clustered, with prominent ridges or flutes which in many instances expand or contract as the plant fills with water or loses its moisture. The tubercles are not conspicuous and grow in rows on the ridges. There are no leaves nor spicules. The spines are of one or two kinds, sharp and dangerous in some species, inconspicuous in others, growing from one-fourth inch to twelve inches in length. The flowers are funnel-form, of brilliant or delicate colorings, large and showy, and unlike many cactus blossoms are fragrant, often with a pronounced spicy odor. In some instances they crown the candelabralike branches in a becoming aureola of light, giving the effect of a lighted candelabrum; hence the designation “torch flower” cacti. Most species bloom only at night. As a rule the calyx tube is found to be very long. The fruit is usually quite large, has shallow tubercles, and is covered with many scales, but is rarely spiny.
How to grow
Only a few of the different kinds of the Cereus Group grow well from cuttings, including Cereus serpentinus. Set the cuttings of such plants as this Serpent Cactus a few inches deep in moist sandy soil and irrigate sufficiently to keep the soil moist. The cuttings grow best in part shade. Cereus plants grow readily from seeds sown in sandy loam mixed with a small amount of pulverized charcoal and some leaf mold; plant in pots or flats one-fourth inch to one inch deep in the soil in partial shade, and keep the soil moist. The young plants can be transplanted to pots when one-half inch to one inch tall. They grow indoors or out; a southern exposure is preferable, being warmer and more sunny.
Caterpillar Cactus; Creeping Devil Cactus; Chirinola (Cereus eruca)
(Named “eruca,” or “caterpillar cactus,” because the stems turn upward at their tips, resembling a caterpillar, head and body)
How to identify and how it grows
The prostrate stems, three to nine feet long, lie flat on the ground with their tips upturned, resembling huge caterpillars. They grow in light sandy soils or sand, and root from below, the tips of the stems elongating and growing forward, the bases of the stems dying; thus the plant slowly moves forward over the sand. These prostrate stems, two or three inches in diameter, are very spiny, with fifteen radial and four central spines clustering an inch or so apart on the twelve to seventeen ridges which run lengthwise on the stems. These fierce, sharp thorns are dark brown and dull tan and turn white with age; the tips are translucent yellow. The radials are less than an inch long and flattened, the centrals grow to two inches in length, one very stout and strongly flattened, resembling a dagger and with a white body. The large flowers are bright yellow and grow four or five inches in length, narrow and funnel-shaped, about two inches across. The fruit is very spiny; but the thorns fall away at maturity, and it becomes quite edible and is relished by Indians and Mexicans.