Cròtons. About twenty-eight species, few of them deserving cultivation; but the genus is celebrated for its beautiful C. pìctus, leaves oblong-lanceolate, variegated with yellow, and stained with red, flowers small green, on axillary spikes. C. variagàtus, variety latifòlia, is finer than the original variagàtus, the nerves in the leaves are yellow, and the leaves lanceolate, entire and smooth. To make them grow freely, give the warmest part of the Hot-house, and drain the pots well.
Cérberas. About twelve species of strong growing trees, full of poisonous juice. C. thevètia is an elegant plant, with accumulate leaves, and large, nodding, yellow, solitary, fragrant flowers, proceeding from the axil; C. ahoùai produces a nut which is deadly poison. C. odàllam, once C. mànghas, has large star-like flowers, white, shaded with red. They are principally East India plants, and require great heat.
Cycas, four species, generally called Sago palm, as an English name. The plant that Sago is extracted from, belongs to another genus, (see Sàgus.) C. revolùta is a well known palm, and will keep perfectly well in the Green-house. We have seen a beautiful specimen of it which is kept every winter in the cellar, but those that are kept so cool in winter only grow every alternate year, while those that are kept in the Hot-house grow every year, which shows that heat is their element. C. circinàlis is a large growing species; the fronds are much longer, but not so close and thick. C. glaùca is a fine species; the foliage is slightly glaucous. They require plenty of pot room, are much infested with the small white scaly insect, and ought to be frequently examined and carefully washed as prescribed in January.
Combrètums. Nine species of beautiful flowering climbing plants, standing in very high estimation. The leaves of the principal part of them are ovate, acute, flowers small but on large branches, the flowers all coming out on one side of the branch. They have a magnificent effect. C. èlegans, red; C. formòsum, red and yellow; C. pulchéllum, scarlet; C. comòsum has crimson flowers in tufts; C. purpùreum is the most splendid of the genus. It was first cultivated in 1818, and so much admired, that the whole of the species as soon as introduced, was extravagantly bought up, and none of them has retained their character, except C. purpùreum, which is now called Poívrea coccínea. The flowers are bright scarlet, in large branches, blooming profusely from April to September, and flower best in a pot. When planted in the ground it grows too much to wood, carrying few flowers. This plant ought to be in every Hot-house.
Cràssula. This genus has no plants in it attractive in beauty. Several beautiful plants in our collections belong to Ròchea and Kalosánthus. There is a strong growing succulent plant, known in our collections as C. falcàta, which is R. falcàta. It seldom flowers; the minor variety blooms profusely every year from May to August, and has showy scarlet flowers in terminale panicles. The plants known as C. coccínea and C. versícolor are now given to the genus Kalosánthus. The flowers of the former are like scarlet wax, terminale and sessile; K. odoratíssima has yellow terminale sweet-scented flowers. They require very little water, only a few times in winter, and about twice a week in summer; they are all desirable plants.
Córyphas, (Large fan Palm,) five species of the most noble and magnificent of palms. C. ambraculífera, the fronds or leaves are palmate; in Ceylon, where the tree is indigenous, they are frequently found fifteen feet wide and twenty feet long. Knox says they will cover from fifteen to twenty men, and when dried will fold up in the shape of a rod, and can be easily carried about, and serve to protect them from the scorching sun. C. talièra, now Talièra bengalénsis, being stronger, is of great utility for covering houses. They do not grow to such immense extent in artificial cultivation, but require large houses to grow them.
Crìnums, about one hundred species, chiefly stove bulbs, many of them beautiful. Those that are of great celebrity are C. cruéntum, colour red; C. scàbrum, crimson and white; C. amàbile, purple and white; the neck of the bulb of the latter is long and easily distinguished from its purplish colour, and is considered the finest of the genus. Several specimens of it are in our collections. Their flowers are in umbels, on a stalk from one to three feet high; corolla funnel shaped; petals recurved. They require large pots to make them flower well, and when growing to be liberally supplied with water.
Cyrtànthus, a genus of Cape bulbs, containing nine species, and will do very well in the Green-house, but we find the assistance of the Hot-house a great advantage. They are closely allied to Crìnum. The tubes of the flowers are long and round, with various shades of orange, yellow, red, and green. C. odòrus, C. striátus, C. oblíquus, and C. vittàtus, are the finest. When the bulbs are dormant, which will be from October to January, they should not get any water; before they begin to grow, turn the bulb out of the old earth, repotting it immediately. At this time they should be potted with the balls of earth entire, which will cause them to flower stronger.
Caryophyllus aromáticus, is the only species, and the tree that produces cloves. The whole plant is aromatic, and closely allied to Myrtus; the flowers are in loose panicles, the leaves oblong, accuminate, entire. It is a fine evergreen. Pots must be well drained.
Dillènias, three species of fine plants, with beautiful foliage. D. speciòsa has produced considerable excitement in our collections. The leaves are elliptic, oblong, simply serrated, nerves deep; the flower is white, with five bold petals, centre filled with barren anthers; it has not been known to flower in America. D. scándens has ovate, simply serrated leaves, but is not known as to flower; it is a fine climber.