oft and watery, spineless, the
cushions distant, and sometimes bearing a few very short bristles.
Flowers at the extremities of the branches, 11/2 in. long, composed of
numerous imbricating, scale-like petals, curving inwards, and coloured
crimson. Fruit flat-topped, 2 in. long, red; pulp reddish; seeds black.
It is a native of tropical South America, whence it was introduced in
1688. It requires stove treatment, and blossoms in August. This is one
of the most useful of the genus, on account of its being the kind
chiefly employed in the cultivation of cochineal. It is one of the
easiest to manage, requiring only a rather dry atmosphere, plenty of
light, and a temperature not lower than 50 degs. in winter. Syn. Nopalea
cochinellifera.

O. corrugata (wrinkled).--Stem not more than 2 ft. high; joints
cylindrical, wrinkled all over, about 2 in. long, covered with cushions
of white hair or bristle-like spines. Flowers 11/2 in. across,
reddish-yellow, produced in August. A native of Chili, whence it was
introduced in 1824. It may be grown in an ordinary greenhouse, on a
shelf near the glass, and exposed to full sunshine.

O. curassavica (Curassoa); Pin-pillow.--Branches spreading; joints
cylindrical or club-shaped, dark green, bearing numerous cushions of
woolly bristles, and long, white, very sharp-pointed spines. Flowers
3 in. across, greenish-yellow, borne on the young joints in June.
Introduced from Curassoa in 1690. A free-growing plant under favourable
conditions, and one requiring stove treatment. It has been cultivated in
gardens almost as long as any species of Cactus. There are several
varieties of it known, differing from the type in habit, length of
spine, or shade of colour in the flower.

O. cylindrica (cylindrical).--Stem and joints cylindrical, the latter
covered with spindle-shaped tubercles, each one crowned with a tuft of
fine, hair-like, whitish spines, one or two in each tuft being stiff,
and sharp as needles. The leaves are fleshy, cylindrical, 1 in. or more
long, and they remain on the joints longer than is usual in Opuntias.
Flowers crowded on the ends of the branches, each 1 in. in diameter,
scarlet; they are developed in June. This plant is said to grow to a
height of 6 ft. or more in its native habitat, but under cultivation it
is rarely seen more than 3 ft. high; it was introduced in 1799. It is
handsome and distinct enough to be worth growing. It requires stove or
greenhouse treatment, but rare