Species.

E. campylacantha. (curved-spined); Bot.  Mag. 4567.—­Stem 1 ft. or l1/2 ft. high, globe-shaped, with a somewhat pointed top, the sides divided into from fourteen to sixteen ridges, with tubercled edges, bearing clusters of about ten strong brown spines, which are stellately arranged, a central one projecting outwards, then suddenly curving upwards, and measuring 3 in. in length.  The flowers are developed from the ridges on the side of the stem; they are 6 in. long, the tube shaped like a trumpet, brownish in colour, and clothed with tufts of short black hairs; petals arranged in three rows, spreading so as to form a limb 21/2 in. across, pale rose-coloured, with a large cluster of yellow-tipped stamens, forming a disk-like centre.  This species is a native of Chili, and was introduced in 1831.  It blossoms in spring and summer.  The long curving central spine and remarkable length of the flower-tube distinguish it from the other kinds.  It may be grown in a cool greenhouse, where it will thrive, if kept freely watered during summer and rested on a dry, sunny shelf in winter.  It is rare in English collections, but frequently occurs in Continental gardens.

E. cristata (crested); Bot.  Mag. 4687.—­Stem globe-shaped, 1 ft. high, slightly narrowed towards the top; ridges fifteen, 1 in. deep, sharply angular, the edges bearing tufts of spreading, yellowish spines, over 1 in. long, slightly curved, and tipped with red.  Flowers creamy-white, springing from the ridges on the top of the stem; tube 4 in. long, clothed with tufts of black hairs, and surmounted by a whorl of reddish-yellow sepals, above which are two rows of broad-spreading petals.  The width of the flower is over 6 in., and the stamens are arranged in a corona-like whorl inside the petals.  This very fine Cactus is a native of Bolivia, whence it was introduced in 1850.  When in flower, the broad, long-tubed, pale-coloured blossoms equal in beauty those of the Night-flowering Cereus.  It blossoms in July.  It thrives if kept in a warm, sunny greenhouse, but must be liberally treated in summer, so as to induce vigorous growth, and then be subjected to complete rest in winter in full sunlight, or it will not flower.

E. c. purpurea (purple ).—­This variety differs from the type in having deep rose-coloured flowers and a slightly longer tube.  It is impossible to find among all the species of the Cereus section a more beautiful plant than this; the size of the flowers, their rich colour, their developing three or four together in the month of July, being almost exceptional, even among Cactuses.  A splendid example of it was flowered at Kew in 1846 for the first time.  It thrives under the conditions recommended for E. cristata.  This variety is often made very sickly by treating it as a tropical Cactus, and, like most of these plants, if once it gets into a bad condition, it remains so a long time, in spite of liberal and careful treatment.  So many of the Cactuses found in cool regions are ruined by an excess of heat in winter, and a close atmosphere during their season of growth, that too much attention cannot be given to the question of temperature in relation to their cultivation in English gardens.