119. Dorstenia Contrajerva, Linn.; and Dorstenia brasiliensis, Lam.

Fig. 293. Dorstenia Contrajerva. Sex. Syst. Tetrandria, Monogynia.

History.—The earliest notice of this plant is that by Monardes, [Clusius, Exoticorum, lib. x. p. 311.] who states that the word contrayerva is the Indo-Spanish term for alexipharmic or counterpoison. In 1581, Clusius [Ibid. p. 83.] received from Sir Francis Drake a root, which he called, after the donor, drakena radix, and which has been supposed to be contrayerva root.

Botany. Gen. Char.—Monoecious. Flowers arranged upon a fleshy receptacle, usually flat and expanded, and extremely variable in form: males on the surface of the receptacle, 2-lobed, fleshy, diandrous; females immersed in the receptacle, also 2-lobed in most species. Ovary 1—2-celled, with a single suspended ovule in each cell. Style 1. Stigma 2-lobed. Achenia lenticular, imbedded in the fleshy receptacle, from which they are projected with elasticity when ripe.—Dwarf herbaceous plants with scaly rhizomata (Lindley).

Species.—1. D. Contrajerva, Linn.—Caulescent; stem covered with spreading green scaly stipules. Leaves palmate; the lobes lanceolate, acuminate, coarsely serrated and gashed, occasionally almost pinnatifid. Receptacle on a very long stalk, quadrangular, wavy, or plated (Lindley). A native of New Spain, Mexico, Peru, Tobago, St. Vincent's (Willd.). The root of this is not met with in commerce.

2. D. brasiliensis, Lam.—A native of Jamaica, Brazil, and Trinidad. This yields the contrayerva root usually met with in the shops.

Description.—The contrayerva root (radix contrajerva) usually found in the shops, is imported from the Brazils. It consists of an ovoid or oblong rootstock, terminating inferiorly in one or several long, tapering, more or less curved root-fibres. From the sides of the rootstock also arise numerous slender fibres. Externally the colour is yellowish-brown. The odour of the root is peculiar, but aromatic. The taste is warm, bitterish, slightly acrid.

I have also found another kind of contrayerva root in the shops. The root-stalk is smaller, cylindrical, blackish-brown, with fewer fibres. The receptacle and leaves are attached; the latter are reniform. Is this the drakena radix of Clusius?

Composition.—The root has not been analyzed. It contains, according to Geiger, [Hand. d. Pharm.] volatile oil, bitter extractive, and starch. To which may be added resin, free acid, and woody fibre.

Physiological Effects.—Stimulant, tonic, and diaphoretic. Its operation is very analogous to that of serpentary root, between which and the rhizome of the sweet flag it deserves to be arranged. The root of the Dorstenia brasiliensis often proves emetic. [De Candolle, Essai sur les Propriétés Méd.]

Uses.—Obsolete, or nearly so. It has been employed in fevers of a low type, and in other diseases requiring a mild, stimulant, and diaphoretic treatment.

Administration.—The dose of the root in powder is ℈j or ʒss. The infusion (prepared by digesting from fʒv in f℥vj of boiling water) may be given in doses of f℥j or f℥ij. The pulvus contrajervae compositus (composed of powdered contrayerva root ℥v, and prepared shells lb jss) is no longer officinal.

The Elements of Materia Medica and Therapeutics, Vol. II, 3th American ed., was written by Jonathan Pereira in 1854.