Spec. Plant Willd. i. 682. Cl. 4. Ord.l. Tetrandria Monogynia. Nat. ord. Artocarpeae. G. 244. Receptacle common, one-leafed, fleshy, in which solitary seeds are nestled (or placed in sockets without attachment). Species 5. D. Contrajerva, Contrayerva, Med. Pot. 3d edit. 705.

t. 240. Officinal. Contrajerva, Lond. Dorsteniae Contrayervae radix, Edin. Contrajerva root.

Syn. Contrajerva (F.), Giftwurzel ( G.), Contrajerva (Dutch), Contraherva (Port.), Contrajerva (I.), Contrahierba (S.).

This is a perennial plant, a native of Peru, Mexico, and some of the West India islands. The root is fusiform, knotty, and branching, compact, furnished with many rough fibres; externally of a brown colour, and internally whitish. It sends up several leaves, which are about four inches in length, and the same in breadth; of an irregular shape, but in general deeply lacinated into five or seven obtuse parts; and placed on long radical footstalks, winged towards the leaves. The fructification, which is remarkable, and on radical stalks or scapes, which rise about four inches high, is a fleshy receptacle, shaped like an animal placenta, about an inch long, and three fourths of an inch broad, placed vertically; and containing on the upper surface very small, scarcely conspicuous, flowers, situated closely together, immersed in the receptacle, and occupying the whole of its disc. The capsule possesses an elastic power when ripe, by which the seeds are thrown out with considerable force.

Monardus is the first author who mentions this root, which, he says, is called Contrajerva1 by the Spanish Indians, on account of its alexipharmic qualities. Dr. Houston 2, however, asserted that the officinal contrajerva was the root of two other species of Dorstenia, the D. Hoastonia and D. Drakena of Willdenow; but the British Colleges follow the authority of Linnaeus. It is brought to this country from the West Indies, packed in bales, in pieces of about two inches long.

Qualities.-Contrajerva root has a peculiar but not unpleasant odour, and a bitterish warm taste, leaving a pretty lasting impression on the tongue. It preserves its qualities when dried, and in the state of powder. Both water and alcohol, assisted by heat, extract its virtues. The watery decoction is of a dark brownish red colour, and exceedingly mucilaginous.-The alcoholic tincture reddens litmus paper, is not altered by a solution of sulphate of iron, but is precipitated by water.

Medical properties and uses.-This root is a stimulant sudorific and tonic. Huxham and Pringle first pointed it out as a remedy well suited to fevers of a typhoid type; and it is often employed in malignant eruptive diseases, dysentery, and in some kinds of diarrhoea. It is also useful in atonic gout, chronic rheumatism, and the fever attending dentition in weak infants.

The dose of the powdered root is from grs. x. to 3 ss.; but it is seldom used alone.