No less than three sections of Cactuses, viz., the above, Echinocactus, and Echinocereus, owe their names to their hedgehog-like stems. From a horticultural point of view, there is perhaps no good reason for keeping the above three genera and Cereus separate; but we follow Kew in the arrangement adopted here. The genus Echinopsis, as now recognised by most English botanists and cultivators, comprises about thirty species, most of which have been, or are still, in cultivation. They are distinguished from Echinocactuses by the length of their flower tube, from Cereuses by the form and size of their stems, and from both in the position on the stem occupied by the flowers. They are remarkable for the great size, length of tube, and beauty of their flowers, which, borne upon generally small and dumpy stems, appear very much larger and handsomer than would be expected.
The distribution of Echinopsis is similar to that of Echinocactus, species being found in Chili, Bolivia, Peru, Brazil, Mexico, &c. They grow only in situations where the soil is sandy or gravelly, or on the sides of hills in the crevices of rocks.
Cultivation.—The growing and resting seasons for Echinopsis are the same as for Echinocactus, and we may therefore refer to what is said under that genus for general hints with regard to the cultivation of Echinopsis in this country. The following is from the notes of the late Curator of the Royal Gardens, Kew (Mr. J. Smith), as being worthy the attention of Cactus growers. Writing about Echinopsis cristata, which he grew and flowered exceptionally well, he says: “This showy plant is a native of Chili, and, like its Mexican allies, thrives if potted in light loam, with a little leaf mould and a few nodules of lime rubbish. The latter are for the purpose of keeping the soil open; it is also necessary that the soil should be well drained. In winter, water must be given very sparingly, and the atmosphere of the house should be dry; the temperature need not exceed 50 degs. during the night, and in very cold weather it may be allowed to fall 10 degs. lower, provided a higher temperature (55 degs.) be maintained during the day. As the season advances, the plants should receive the full influence of the increasing warmth of the sun; and during hot weather, they will be benefited by frequent syringing overhead, which should be done in the evening. It is, however, necessary to guard against the soil becoming saturated, for the soft fibrous roots suffer if they continue in a wet state for any length of time.”
None of the species require to be grafted to grow freely and remain healthy, as the stems are all robust enough and of sufficient size to take care of themselves. The only danger is in keeping the plants too moist in winter, for although a little water now and again keeps the stems fresh and green, it deprives them of that rest which is essential to the development of their large, beautiful flowers in summer.