ll times. It is represented at Kew
by very large specimens; one of them, which was recently cut down, had a
stem 12 ft. high and an enormous head of dark, green joints. Its head was
planted as a cutting.

O. occidentalis (Western).--Stem stout, woody, with innumerable
branches, wide-spreading, often bent to the ground. Joints 9 in. to 12 in.
long by about 6 in. broad, flattened, as many as 100 on one plant.
Cushions nearly 2 in. apart, with small, closely-set bristles and
straight spines from 1/2 in. to l1/2 in. long. Flowers produced in June on the
ripened joints, nearly 4 in. in diameter, orange-yellow. Fruit 2 in. long,
"very juicy, but of a sour and disagreeable taste." This is an
exceptionally fine plant when allowed sufficient space to develop its
enormous branches and joints; it is a native of the Western slopes of
the Californian mountains. It should be planted in a bed of rough, stony
soil, in a dry greenhouse. Possibly it is hardy, but it does not appear
to have been grown out of doors in England.

O. Parmentieri (Parmentier's).--Stem erect. Joints cylindrical, "like
little cucumbers." Cushions about 1 in. apart, arranged in spiral rows,
and composed of short, reddish bristles, with two or three
straw-coloured spines, 1 in. long. Flowers reddish, small. The plant is a
native of Paraguay, and is rarely heard of in cultivation. It requires
stove treatment.

O. Parryi (Parry's).--Stem short. Joints club-shaped, 4 in. to 6 in.
long, very spiny, the cushions elevated on ridge-like tubercles.
Bristles few, coarse, and long. Spines very numerous, varying in length
from 1/4 in. to 11/2 in.; central one in each cushion much the broadest, and
flattened like a knife-blade, the others being more or less triangular.
Flowers yellowish-green, on the terminal joints, which are clothed with
star-shaped clusters of bristle-like spines, the flowers springing from
the apex of the joint, and measuring 11/2 in. across. A native of Mexico,
where it grows on gravelly plains. This distinct plant is in cultivation
at Kew, in a warm greenhouse, but it has not yet flowered.

O. Rafinesquii (Rafinesque's); Fig. 84.--A low, prostrate, spreading
plant, seldom exceeding 1 ft. in height, the main branches keeping along
the ground, the younger ones being erect. The latter are composed of
flat, obovate joints, 4 in. to 5 in. long by 3 in. in width, fresh green in
colour; spines very few, mostly only on the upper edge of the last-made
joints