in botany: A genus of the monogynia order, belonging to the icotandria class of plants; and in the natural method ranking under the 13th order, Succulentae. The calyx is monophyllous; superior, or above the receptacle of the fruit imbricated; the corolla polypetalous; the fruit an unilocular, polyspermous berry. To this genus Linnæus has added the cactus and opuntia. There are 24 species, all natives of the West Indies and Mexico.

The cacti are plants of a singular structure, but especially the larger kinds of them; which appear like a large, fleshy, green melon, with deep ribs, set all over with strong sharp thorns; and, when the plants are cut through the middle, their inside is a soft, pale-green, fleshy substance, very full of moisture. The fruit of all the species is frequently eaten by the inhabitants of the West Indies. The fruits are about three quarters of an inch in length, of a taper form, drawing to a point at the bottom toward the plant, but blunt at the top where the empalement of the flower was situated. The taste is agreeably acid, which in a hot country must render the fruit more grateful.

The cochineal animals are supported on a species called cactus cochenillifer.—The flower of the cactus grandiflora (one of the creeping cerefes) is said to be as grand and beautiful as any in the vegetable system: It begins to open in the evening about seven o'clock, is in perfection about eleven, and fades about four in the morning; so that the same flower only continues in perfection about six hours. The calyx when expanded is about a foot in diameter, of a splendid yellow within, and a dark brown without; the petals are many, and of a pure white; and the great number of recurved filaments surrounding the style in the centre of the flower, make a grand appearance, to which may be added the fine scent, which perfumes the air to a considerable distance. It flowers in July.