XXV. THE CACTUS FAMILY. 423 



FAMILY XXV. THE CACTUS FAMILY. CACTACEJE. 



Perennial, shrub-like or arborescent plants, of peculiar appear- 

 ance and structure. The root is woody and fibrous. The trunk 

 hemispherical, or cylindrical, branched or jointed, angular, rib- 

 bed, winged, or with mammillary projections, or plane; — fleshy, 

 with a thick, mostly green, smooth bark, and interspersed with 

 few or numerous woody fibres. The leaves are usually want- 

 ing and their place supplied by bundles of thorns. The flowers, 

 often large, splendid and fragrant, consist of a calyx of many 

 divisions, partly colored and petal-like, proceeding from the ex- 

 terior of the ovary and passing by imperceptible gradations into 

 the petals, which are very numerous, and arranged spirally or 

 in several series. Within these, and, like them, proceeding from 

 the lining of the calyx-tube, are the numerous, slender stamens. 

 The base of the calyx is the 1 -celled ovary, containing a great 

 number of ovules attached to seed-nourishing projections from 

 the walls. The style is single, and terminates in 3 or more 

 stigmas. The fruit is a fleshy, umbilicated berry, in the pulp 

 of which the numerous seeds, enclosed in a double integument, 

 nestle. The fruit is pleasantly acidulous, eatable, and, in its 

 native tropical climates, grateful. 



De Candolle enumerates about 180 species, all indigenous to 

 America, and most of them to the warmest regions, where they 

 delight in warm, arid situations, exposed to the sun. Some 

 species have been perfectly naturalized on the coast of the Med- 

 iterranean, and many are cultivated in conservatories, for their 

 singularity or the extreme beauty of their flowers. A species 

 of cactus is sometimes used in the south of Europe as a hedge. 

 Another species, Opuntia coccinillifera, a native of Mexico, sus- 

 tains the cochineal insect, from which is obtained the beautiful 

 scarlet of such importance in commerce. 



Some species are found on the sandy wastes at the foot of the 

 Rocky Mountains. A single species occurs in Massachusetts. 



