Calathèa zebrìna, frequently known as Maránta zebrìna, and now Phrynum zebrìnum, is a plant unique in its appearance. The large elongated ovate leaves are beautifully striped with green and dark purple, and called Zebra plant. It has light blue flowers in ovate spikes, about the size of large pine cones. It is a herbaceous plant; but in the warmest part of the Hot-house retains its splendid foliage; requires a very liberal supply of water, and ought to be in every collection.
Cánnas, about thirty species, several of them deserving cultivation both for flower and foliage; they are principally natives of the West Indies, and might all be easily obtained. The finest are C. gigántea, has large leaves and orange flowers; C. limbàta, flowers scarlet and yellow; C. díscolor, has large cordate, accuminate leaves of a crimson colour, the flowers are scarlet; C. iridiflòra, has large crimson nodding flowers, very different from any of the others, and the finest of the genus. They all, while in a growing state, require a liberal supply of water; and being herbaceous plants watering ought to be given up about the first of November, and renewed about the first of January, thus giving them a cessation which they require to flower freely; but when water is constantly given, which is the general plan in our collections, they continue to push weak shoots and few flowers.
Cáctus. This extensive genus is curious, grotesque, interesting, and varied in character and habit; is now divided into six distinct genera according to their natural appearance and habit. We will describe a few of each genus, none of which going under the name of Cáctus, we will give them the six following.
Mamillàrias, above twenty species, and are those which are covered with roundish bearded tubercles, and with small red and white flowers. M. coccínea; M. simplex; M. pusílla, and M. cònica, are good species, and will do well with water five or six times during summer.
Melocáctus, seven species, and are those that are roundish with deep and many angles, with spines in clusters on the top of the angle. M. commùnis, is the Turk's cap, named from having an ovate conate crown upon the top, from which proceed the small red flowers.
M. macránthus, has large spines; M. pyramidàlis, is a conical growing species. These require the same treatment as the last.
Echinocáctus, about twenty species; are those that have many deep angles, and have a remarkable swelling, with each parcel of spines; E. gibbòsus; E. crispàtus; E. recúrvus; are curious in appearance, with small white and purple flowers. These three genera in most collections are not well known specifically, but it is easy to discriminate which genus they are connected with.
Cèreus. This is the most magnificent genus with regard to the magnitude and beauty of the flowers, but not so closely allied. It takes in all those of a trailing or erect growing habit, having spines in clusters, solitary, or spineless. C. peruviànus and C. heptagònus, grow very erect, and to the height of thirty or forty feet in Peru and Mexico, where they plant them close together as fences, and they are in a few years impenetrable. C. flagellifórmus is a well known creeping free flowering species, has ten angles; will keep in a good Green-house, and produce in May and June a great number of blooms. The petals are of a fine pink and red colour; the tube of the flower is long, and will stand a few days in perfection, when others come out successively for the space of two months, and during their continuance make a brilliant appearance. C. grandiflòrus is the celebrated "Night-blooming Cereus." The flowers are very large, beautiful, and sweet-scented. They begin to open about sun-down, and are fully expanded about eleven o'clock. The corolla, or rather calyx, is from seven to ten inches in diameter, the outside of which is a brown, and the inside a fine straw yellow colour; the petals are of the purest white, with the stamens surrounding the stile in the centre of the flower, which add to its lustre, and make it appear like a bright star. Its scent is agreeable, and perfumes the air to a considerable distance; but these beauties are of momentary duration. By sunrise they fade, and hang down quite decayed, and never open again.[E] One of these ought to be in every collection, and if trained up a naked wall will not occupy much room, and grow and flower profusely. They need very little water. C. speciosíssimus has most beautiful large flowers, about six inches diameter; the outside petals are a bright scarlet, those of the inside a fine light purple. One flower lasts a few days, and a large plant will produce every year from ten to twenty flowers, blooming from May to August. It has flowered in some of our collections, and is highly esteemed. C. triangulàris has the largest flower of the Cacteæ family; the bloom is of a cream colour, and about one foot in diameter. In its indigenous state, it produces a fine fruit called "Strawberry Pear," and is much esteemed in the West Indies as being slightly acid, and at the same time sweet, pleasant, and cooling. It seldom flowers. C. phyllanthoídes, once Cáctus speciósus, is one of the most profuse in flowering; the branches are ensate, compressed, and obovate, without spines; flowers of a pink colour, about four inches in diameter; the stamens as long as the corolla, with white anthers. It will keep well in a Green-house or Room. If in either of the two latter, give water only a few times during winter. This is becoming a very popular plant. C. Jenkinsòni is a magnificent hybrid from C. speciosíssimus. The flowers are equally as large, and of a brilliant scarlet colour, with a profusion of pure white anthers; is greatly admired, and is only in a few collections. C. Ackermánni is very similar to C. phyllanthoídes, flowering equally as profusely, the colour a bright scarlet, and the scarcest species of the genus that is worthy of notice. C. truncàtus, branches truncated, flowers deep scarlet and tubular, from two to three inches in diameter; the stamens protrude from the corolla; the plant is of a dwarf growth and branched; when in flower it is quite a picture. It is said that there are free and shy flowering varieties of this species, but we doubt it; perhaps it is owing to the cultivation and soil.
[E] They may be preserved if cut off when in perfection, and put in spirits of wine, in a chrystal vase, made air tight. A plant flowered in our collection in May 1830, at 12 o'clock at noon—the only instance of the kind we ever heard of.
Opúntias, about forty species, and are those whose branches are in joints flatly oblong, or ovate, spines solitary, or in clusters. The plants are not so desirable for beauty of flower as the species of the former genus, but many of them are remarkable for their strong grotesque and spiny appearance; besides several of the species are extensively cultivated for the Cochineal insect. The one most valued for that purpose, is O. cochiníllifera, which has only small clusters of bristles upon the oblong ovate joints, and produces small red flowers; C. ficus índica, is also used, but is very spiny.