Dorstenia contrajerva is a plant species in the family Moraceae. It is native to Northern South America and Central America, and is cultivated elsewhere. The species name "contrajerva" is the Latinized form of the plant's Spanish name, "contrahierba", a name for plants used for treating poisoning and venomous bites and stings, and for which its rootstocks are used in folk medicine (as contrayerva). It is the type species of the Dorstenia genus and was first described by Carl Linnaeus in 1753.
Description
Dorstenia contrajerva is a small evergreen perennial plant with a creeping rhizome from which emerges a rosette of leaves with long petioles. Leaves are variably shaped, with plants with lobed and unlobed leaves co-occurring in the same populations. Leaves are up to 20 cm long on petioles up to 25 cm long. When damaged the plant exudes a white latex. Tiny male and female flowers are distributed intermixed on a discoid receptacle of convoluted shape. The fruits are small and contained in a quadrangular container. The tiny seeds are explosively expelled.
Plants acaulescent or nearly so. The stems, if any, are very short and covered with persistent petiole bases. Leaves are often very numerous and crowded. Stipules persistent; petiole 8–25 cm. Leaf blade long-petiolate, oblong-ovate, deltate-ovate, or orbiculate, entire or deeply pinnately or almost palmately lobed, 6-20 × 7–22 cm, sparsely scabrous or pubescent. The lobes acute to acuminate, narrow or broad. Inflorescences: receptacle flat, curved, or undulate, quadrangular or irregularly lobed, accrescent in age and 2–5 cm. wide, scaberulous beneath. On long slender peduncle, 7–25 cm. Drupes somewhat globose, 0.25–1 cm in diameter. Seeds yellowish. 2 n = 30.
In the United States Pharmacopoeia and the National Formulary (1927), the rhizome of Dorstenia contrajerva or Contrayera is described as fusiform, 1–2 headed, 5–7.5 cm long, 12 mm thick, reddish, with an unpleasant odor and acrid, bitter taste.
Distribution
Dorstenia contrajerva is native to southern Mexico, Central America, the Caribbean and northern South America including Peru. It is cultivated in Indonesia (Java) and Malaysia (Malacca), and locally in Africa and South America. In North America Dorstenia contrajerva has been introduced to Florida and is a weed in greenhouses and nurseries. It is sometimes cultivated as a house plant.
Habitat
It grows in shady places in disturbed vegetation in mangroves, savannahs, thickets, and tropical forests.
Cultivation
Dorstenia contrajerva requires part to full shade and a rich soil that should be kept moist but not saturated. Fertilize weekly using a balanced fertilizer diluted to half of the recommended strength. It can become very weedy if the old receptacles are not picked off. The seeds are very viable and germinate on any soil. Repotting can be done at any time of the year. Easily propagated from seed or by division. Fresh seed will germinate in 7 to 14 days.
Use in traditional medicine
In folk medicine in Honduras, the boiled root is used for diarrhea, dysentery, and stomach ache. The slightly roasted and ground root is used to treat intestinal worms and parasites. The crushed root is mixed with water to treat the bites of snakes. In Nicaragua the boiled root is used to prevent diarrhea; minced raw rhizomes are used to treat diarrhea, sickness, stomach upset, indigestion, and worms. In El Salvador it is used for stomachache and to prevent vomiting. In Costa Rica the boiled root is used for diarrhea, and an infusion to lower fever. It is considered useful for diarrhea as well as an emmenagogue. In Mexico the latex is used to heal wounds and the inflorescences are given to teething children. In the Amazon region of Peru it is used as a tonic, against gangrene, and as an antidote for bee and wasp stings. In Argentina, the whole plant is used to treat snakebite. In Venezuela it is used as a sudorific and as a cure for dysentery.
Duke's Handbook of Medicinal Plants of Latin America lists the following medicinal activities: alexiteric, anti-HIV, diaphoretic, diuretic, emmenaggogue, febrifuge, leihmanicide, orexigenic, stimulant, tonic.
The United States Pharmacopoeia and the National Formulary of 1927 says that the root of this plant was used for low fevers, typhoid, diarrhea, dysentery, serpent bites; in decoction, tincture. Maud Grieve writes in her Modern Herbal (1931) that contrayerva given as a powder or decoction is a “Stimulant, tonic, and diaphoretic; given in cases of low fevers, typhoid, dysentery, diarrhoea, and other illnesses needing a stimulant.” In folk medicine it is used to treat bites of poisonous animals.