CONVOLVULUS, BIND-WEED: A genus of the pentandria order, belonging to the monogynia class of plants; and in the natural method ranking under the 29th order, Campanaceæ. The corolla is campanulated and plaited; there are two stigmata; the capsule is bilocular, and the cells are dispergous. Of this genus there is a great number of species, the most remarkable of which are the following.
1. The sepium, or large white bind-weed, is often a troublesome weed in gardens, when its roots are interwoven with those of trees and shrubs, or under hedges, as every small piece of root is apt to grow. It flourishes under moist hedges, and hath white or purplish blossoms. 2. The scammonia, or Syrian bind-weed, grows naturally in Syria. The roots are thick, run deep into the ground, and are covered with a dark bark. The branches extend on every side to the distance of 10 or 12 feet; they are slender, and trail on the ground, and are garnished with narrow, arrow-pointed leaves. The flowers are of a pale yellow, and come out from the side of the branches, two fitting upon each long footstalk: these are succeeded by roundish feed-vessels, having three cells filled with feeds. 3. The purpureus, or convolvulus major, is an annual plant growing naturally in Asia and America, but has been long cultivated in the British gardens. If these plants are properly supported, they will rise 10 or 12 feet high in warm summers. There are three or four lasting varieties: the most common hath a purple flower; the others have a white, a red, or a whitish-blue flower, which last hath white feeds. They flower in June, July, and August, and their feeds ripen in autumn. 4. The nil, or blue bind-weed, rises with a twining stalk 8 or 10 feet high, garnished with heart-shaped leaves, divided into three lobes, which end in sharp points. These are woolly, and stand upon long footstalks. The flowers also come out on long footstalks, each sustaining two flowers of a very deep blue colour, whence their name of anil or indigo. This is one of the most beautiful plants of the genus: it flowers all the latter part of the summer; and in good seasons the feeds ripen very well in the open air. 5. The battatas, or Spanish potatoes, hath esculent roots, which are annually imported from Spain and Portugal, where they are greatly cultivated for the table; but they are too tender to thrive in the open air in Britain. Their roots are like the common potato, but require much more room: for they send out many trailing stalks, which extend six or eight feet every way; and at their joints send out roots which in warm countries grow to be very large bulbs; so that from a single root planted 40 or 50 large potatoes are produced. 6. The canariensis, with soft woolly leaves, is a native of the Canaries; but hath long been preserved in the British gardens. It hath a strong fibrous root, from whence arise several twining woody stalks, which, where they have support, will grow more than 20 feet high, garnished with oblong heart-shaped leaves, which are soft and hairy. The flowers are produced from the wings of the leaves, several standing upon one footstalk. They are for the most part of a pale blue; but there is a variety with white flowers. They appear in June, July, and August, and sometimes ripen feeds here. 7. The tricolor, or convolvulus minor, is a native of Portugal; but hath long been
cultivated in the gardens of this country. It is an annual plant, which hath several thick herbaceous stalks growing about two feet long, which do not twine like the other sorts, but decline toward the ground, upon which many of the lower branches lie prostrate; they are garnished with spear-shaped leaves, which sit close to the branches: the footstalks of the flowers come out just above the leaves of the same joint, and at the same side of the stalks. They are about two inches long, each sustaining one large open bell-shaped flower, which in some is of a fine blue colour with a white bottom; in others they are pure white, and some are beautifully variegated with both colours. The white flowers are succeeded by white feeds, and the blue by dark-coloured feeds; which difference is pretty constant. 8. The soldanella, or sea-bindweed, styled also brassica marina, grows naturally on the sea-beaches in many parts of England, but cannot be long preserved in gardens. It hath many small white stringy roots, which spread wide and send out several weak trailing branches. These twine about the neighbouring plants like those of the common bindweed, garnished with kidney-shaped leaves like those of the lesser celandine. The flowers are produced on the side of the branches at each joint. They are of a reddish purple colour, and appear in July. They are succeeded by round capsules, having three cells, each containing one black feed. 9. The turpethum is a native of the island of Ceylon. This hath fleshy thick roots which spread far in the ground, and abound with a milky juice that flows out when the roots are broken or wounded, and soon hardens into a resinous substance when exposed to the sun and air. From the root shoot forth many twining branches, which twirl about each other, or the neighbouring plants, like the common bindweed. They are garnished with heart-shaped leaves that are soft to the touch, like those of the marshmallow. The flowers are produced at the joints on the side of the stalks, several standing together on the same footstalk: they are white, and shaped like those of the common great bindweed, and are succeeded by round capsules, having three cells containing two feeds each. 10. The jalappa, or jalap, used in medicine, is a native of Haleppo in Spanish America, situated between La Vera Cruz and Mexico. It hath a large root of an oval form, which is full of a milky juice; from which come out many herbaceous twining stalks rising eight or ten feet high, garnished with variable leaves; some of them being heart-shaped, others angular, and some oblong and pointed. They are smooth, and stand upon long footstalks: the flowers are shaped like those of the common greater bindweed, each footstalk supporting only one flower.
Culture. The first and second sorts are propagated by feeds, which must be sown on a border of light earth. The second sort must have some tall stakes placed near them for their branches to twine about, otherwise they will spread on the ground and make a bad appearance. The third sort is annual, and must be propagated by feeds sown on a hot-bed in the spring, and towards the end of May they should be planted out in warm borders, and treated in the same manner with the former. The fourth species is sometimes propagated in this country. The roots must be planted on a hot-bed in the spring; and if the plants
Convulva- are covered in bad weather with glasses, they will pro-
lus duce flowers and some small bulbs from the joints of
|| the stalks: but if they are exposed to the open air, they
Cook. seldom grow to any size. The fifth is propagated by
laying down the young shoots in the spring, which
generally put out roots in three or four months: they
may then be taken from the old plants, and each placed
in a separate pot, which is to be set in the shade
till they have taken new root; after which they may
be placed with other hardy green-house plants till au-
tumn, when they should be removed into the green-
house, and afterwards treated in the same manner as
myrtles and other green-house plants. The turbith
and jalap are too tender to live in this country, unless
they are constantly kept in a stove. The other species
require no particular directions for their cultivation.
Uses. The root of the first sort is a very acrid purgative to the human race, but is eaten by hogs in large quantities without any detriment. The inspissated juice of the second species is used in medicine as a strong purgative; as are also the roots of the jalappa and turpethum. The soldanella has likewise been used with the same intention. Half an ounce of the juice, or a drachm of the powder, is an acrid purge. The leaves applied externally are said to diminish dropsical swellings of the feet. See SCAMMONY, JALAP, and TURPETH.