ich distinguish Cactuses from other plants; they are
also succulent, the leaves and young branches being soft and fleshy.
They appear to have the same peculiar provision for enabling them to
bear long periods of drought without suffering that characterises the
more familiar forms of Cactuses. The development of the spines in this
genus is different from what takes place in all other spiny plants of
this order. In the latter the spines are stoutest and most numerous on
the younger parts of the plant, the older or woody parts being either
spineless, through having cast them, or much less spiny than when they
were younger. Thus, in Opuntia we find few or no spines on the old parts
of the stems of even such species as O. horrida, O. nigricans, &c. In
Echinocactus, too, the spines about the base of old plants are much
fewer, if not entirely cast off, than on the upper part. In Pereskia the
contrary is the case. Taking P. aculeata as an example, this is best
known in gardens as having branches about as thick as a goose-quill,
with ovate leaves, at the base of which there is a pair of curved
spines, 1/4 in. long, and shaped like cats' claws. But this plant when it
gets old has a stem 3 in. in diameter, and clothed down to the ground
with cushions of spines fixed firmly in the bark, each cushion composed
of from twenty to fifty spines, and each spine 1 in. or more in length.
From two to six new spines are developed in the centre of each healthy
cushion annually. It would be absolutely impossible for any animal to
climb an old stem of a Pereskia. In P. Bleo the spines are 2 in. long,
and the cushions are much larger.

The flowers of Pereskias are borne singly or in panicles, at the ends of
the young, ripened branches. In shape, each flower may be compared to a
single Rose, the petals being flat and spreading, and the numerous
stamens forming a compact cluster in the centre. The stigma is erect,
and divided at the top into four or more rays. The fruit is a berry
shaped like a Gooseberry, and covered with minute clusters of short
bristles.

All the species are found in tropical America and the West Indies.

Cultivation.--Although several of the kinds of Pereskia are
sufficiently ornamental to be deserving of a place in gardens as
flowering plants, yet they are rarely cultivated--in England, at least
--for any other purpose than that of forming stocks upon which
Epiphyllums and other Cacti are grafted. Only two species are used,