to be grown in an
intermediate house. It is a charming little Cactus, and quite
exceptional among Opuntias in the colour and abundance of its flowers,
and in the rich colour of its numerous fruits, which usually remain on
the plant several months. The plant, too, has the merit of keeping dwarf
and compact. The small joints separate very easily from the branches,
and every one of them will root and grow into a plant. There is
something very remarkable in the development of the fruits of this kind.
A small branch, or joint, grows to its full length, and a flower-bud
appears in the apex. If examined at this stage, it will be seen that the
ovary occupies only a very shallow cavity in the top of the branch.
After flowering, this ovary grows into the branch, and ultimately the
whole branch is transformed into a pulpy fruit, with the seeds scattered
all through the pulp. This peculiarity is well shown in O. salmiana, and
the development of the fruit can be very easily watched. Many of the
small branches do not flower, although they change to a red colour like
the fruits.

O. spinosissima (very spiny).--Stem erect, woody. Joints very flat and
thin, deep green, ovate or rotund, from 6 in. to 1 ft. long. Cushions 1 in.
apart. Bristles very short. Spines in clusters of about five, the
longest 2 in. in length, brownish-yellow. Flowers reddish-orange, small,
usually only 2 in. across, produced in June. A native of South America;
naturalised in many parts of the Old World. The stem becomes cylindrical
with age, and sometimes is devoid of branches for about 5 ft. from the
ground. The plant requires stove treatment. Probably this kind is only a
form of O. Tuna.

O. subulata (awl-shaped).--Stem erect, cylindrical, even below,
channelled and tubercled above, about 2 in. in diameter. Joints long and
branch-like, with tufts of short, white hair on the apices of the
tubercles, and one or two white, needle-like spines from 1/2 in. to 1 in.
long. At the base of each tuft, from the apex to 1 ft. or more down the
younger branches, there is a fleshy, green, awl-shaped leaf, from 2 in.
to 5 in. long. Ultimately the leaves and spines fall away, the tubercles
are levelled down, and the mature stem is regular and cylindrical, with
tufts of white setae scattered over it. Flowers small, produced in
spring; sepals 2 in. long, green, deciduous; petals small, dull purple,
usually about eight in each flower. Fruit pear-shaped, 4 in. long; seeds
very lar