in botany: A genus of the monogynia order, belonging to the polyandria class of plants; and in the natural method ranking under the 25th order, Putaminæa. The calyx is tetraphyllous and coriaceous; there petals are four; the stamens are long; the fruit is a berry, carnous, unicellular, and pedunculated, or furnished with a footstalk.

There are seven species. The spinosa, or common caper, is a low shrub, generally growing out of the joints of old walls, the fissures of rocks, and amongst rubbish, in most of the warm parts of Europe: it hath woody stalks, which send out many lateral slender branches; under each of these are placed two short crooked spines, between which and the branches come out the footstalks of the leaves, which are single, short, and sustain a round smooth entire leaf. At the intermediate joints, between the branches, come out the flowers on long footstalks; before these expand, the bud with the empalement is gathered for pickling. Those which are last expand in form of a single rose, having five large white petals, which are roundish and concave; in the middle are placed a great number of long stamens, surrounding a style which rises above them, and crowned with an oval germen, which afterwards becomes a capsule filled with kidney-shaped seeds.

Culture. This plant is very difficultly preserved in Britain: it delights to grow in crevices of rocks, old walls, &c. and always thrives best in a horizontal posture; so that, when planted either in pots or in the full ground, they seldom thrive, though they may be kept alive for some years. They are propagated by seeds in the warm parts of Europe, but very seldom in Britain.

Uses. The buds, pickled with vinegar, &c. are brought to Britain annually from Italy and the Mediterranean. They are supposed to excite appetite and assist digestion; and to be particularly useful as detergents and aperients in obstructions of the liver and spleen.