O. Ficus-indica (Indian Fig); Fig. 80.—­Branches erect, 8 ft. to 12 ft. high; joints flat, oval or obovate, about 1 ft. long by 3 in. in width, and 1 in. in thickness.  Stems hard and woody with age.  Cushions 11/2 in. apart, composed of short, yellowish bristles, and very rarely one spine.  Flowers 3 in. to 4 in. across, sulphur-yellow, produced all through the summer.  Fruit 3 in. to 4 in. long, pear-shaped, covered with tufts of bristles, white, yellow, or red when ripe.  It is a native of Central America, whence it was introduced about 300 years ago.  It is now widely spread, in tropical and temperate regions all over the world.  In many parts it is cultivated for the sake of its fruits, which in some of our colonies are used for dessert.  In England it must be protected from damp and cold; it is, therefore, best cultivated in a sunny greenhouse during winter, and placed outside in a position exposed to full sunshine all summer.  Tenore, an Italian botanist, named this species O. vulgaris, and this mistake has led others to consider the North American O. vulgaris (true) and O. Ficus-indica as one and the same species.

[Illustration:  Fig. 80.  FRUITING branch of opuntia ficus-indica.]

O. filipendula (hanging filaments); Fig. 81.—­Stems prostrate, about 1 ft. high, spreading; joints flat, round or oval, about 3 in. long, often less, milky-green in colour.  Cushions 1/2 in. apart, composed of a little tuft of white woolly hair, a cluster of erect, rather long bristles, like a small shaving-brush, and all pointing upwards; spines usually only one in each cushion, and this is slender, deflexed, white, and from 1 in. to 2 in. long.  Sometimes the joints are wholly spineless.  Flowers 21/2 in. in diameter, purplish, very handsome, produced in May and June.  Fruit not known.  The roots of this species bear tubers often 1 in. in thickness, and several inches in length, and these tubers will grow into plants if severed and planted.  It requires stove treatment.  Native country, Mexico.

[Illustration:  Fig. 81.  Opuntia filipendula.]

O. frutescens (shrubby).—­A thin-stemmed, copiously-branched species.  Joints almost continuous, like ordinary branches, from 2 in. to 6 in. long, the thickest not exceeding 1/4 in.  Cushions on raised points or tubercles, each consisting of a small tuft of hair, inclosed in a row of bristles, and one long, central spine, often exceeding 2 in. in length.  When young, the spines are inclosed in a thin, bony sheath.  Flowers scattered along the younger branches, 1 in. across, greenish-yellow, borne in June.  Fruit 1 in. long, pear-shaped, smooth, scarlet, with tufts of bristles all over it, and a depression in the apex.  Mexico.  This forms an interesting pot-plant when properly cultivated.  It should be grown in a warm greenhouse.