Cacti of the Southwest

Genus Echinocereus Engelmann

Genus Echinocereus Engelmann The Echinocerei make up one of the largest genera of cacti, both in number of different species and in number of individu­ als found growing in the area of this study. Many of its mem­ bers are collected and grown by cactus fanciers all over the world as great favorites because of the beauty of their flowers as well as of the plants themselves. The name of the genus is composed of two words: echinos, meaning spiny, which refers to the very spiny covering of the typical members of this genus, and cereus, which means “wax candle,” a reference to the stately appearance of the stems of the upright species. The Echinocerei are oval, conical, or cylindrical cacti, always with ribbed stems. The vertical ribs of some species are more or less divided into swellings which may be called warts or tuber­ cles, but these are never completely separated from one another as in some other genera, so the ribs are always an outstanding character of them all. These cacti are usually very spiny, as their name implies, and these spines may be straight or curved, but are never hooked, as is common in some other groups. The stems of Echinocerei are always low as compared with many of their relatives. Most of them are well under twelve inches long when mature, and the few in the Southwest which sometimes surpass that do not usually exceed twenty-four inches long. These stems are erect in most species, but in a few they lie partly or entirely prostrate upon the ground. The plant body of some species remains a single, unbranched stem throughout life. Others cluster or branch sparingly only when very old; but many regularly form clusters of stems al­ most from the start. In some these clusters are made up of only a few stems, but in a few of them one plant may with age be­ come a huge, caespitose clump of as many as a hundred or more stems, These stems are never divided into joints however. The flowers of this genus are borne on the ribs at the spine­ bearing areoles, developing just above the uppermost spines of the areoles, where they literally burst through the epidermis of the stem. They may be produced from almost any point on the stem, different species bearing them high or low, but most com­ monly they appear on the sides of the stems a little below the tips. The flowers are usually very large and beautiful, so beautiful that many fanciers pick one or another species in this genus as the most beautiful of our native cacti. However, a few of the Echinocerei have small and inconspicuous greenish flowers. The petals of some species remain only partly open, making the flowers funnel-shaped, while those of others open very widely. A perianth tube is always present. The outer surface of the ovary is always spiny and sometimes woolly as well. The stigma lobes are always green on all of our species. The fruits produced by these cacti are always fleshy, thin­ skinned, and often edible. Those of some species are considered delicacies. Something of their character may be imagined from the fact that a number of them are known by the common name of “strawberry cacti.” These fruits are also spiny, but the spines become loosened as the fruits mature, and may be easily brushed off. The members of the genus Echinocereus inhabit a wide belt of the North American continent from Utah and Wyoming south throughout most of northern Mexico to a little beyond the lati­ tude of Mexico City, and from central Oklahoma and Texas on the east to the Pacific on the west. ‘Within this huge area more than eighty species have been described by various authorities, but many of these so intergrade that later students have combined various ones. The result is that almost every book or article on this genus has at least a slightly different method of listing them, depending upon the taxonomic philosophy of the writer as well genus Echinocereus engelmann 11 as upon his knowledge of these cacti. This has caused much con­ fusion, and makes it necessary for us to deal with many authors and names in order to know exactly what plant we have before us. I will attempt to make or follow no formal classification of the species within the genus because it is too large a group and we have in the area of...