Cancerillo is is an erect, evergreen perennial subshrub that grows to 1 m in height. It has a woody base, stems with milky sap, and dark green lance-shaped leaves 5-15 cm long. It produces showy orange and red flowers in umbels with brilliant red-purple centers. It blooms almost continuously which has made it a favorite as a cultivated plant in gardens and attracting bees, hummingbirds and butterflies to the garden. One of its common names is "butterfly weed" as the blooms are quite attractive to butterflies, especially Monarch butterflies. The fruits are spindle shaped 3-4 inch pods which eventually split open to release little flat seeds that drift away on silky strands.

The scientific name refers to the Greek god of medicine, Asclepius, because of the long regarded medicinal qualities of the plants in this genus. However, many species in the family are poisonous and contain cardiac glysosides; the toxicity of which may cause death in livestock or humans. In the milkweed family, this particular species is native to South America and the Amazon rainforest. Because of its popularity as an ornamental plant, it has become a naturalized weed in tropical and subtropical pastures, fields and disturbed areas throughout the world, including central and southern Florida and Texas.

The milkweed family is a large one with many species represented. Most of the milkweeds, reflective their common name, have a milky, usually toxic juice which flows freely from every cut or break of the plant.

TRIBAL AND HERBAL MEDICINE USES

Root extracts of cancerillo are widely used in South America an emetic (induces vomiting) and laxative. The leaves and flowers of the plant are considered toxic and reports of smaller grazing animals dying from consumption of the leaves have been reported. In the Suriname rainforest, an extract of the root is used an emetic, expectorant, and laxative and employed for warts, fever, and to induce vomiting. A decoction of the entire plant is used as an abortifacient. The roots are commonly known as "pleurisy root" and used as an expectorant for pneumonia and pleurisy and other lung problems. In Jamaica, a poultice of the root is used to treat ringworm and to stop bleeding. The Caribs considered the root to be good medicine to reduce fevers, and in Africa it has been used for intestinal troubles with children.

In Western Canada and the USA, the milky sap of the stems have been used to treat warts and skin parasites, and the roots are prepared in decoctions for constipation, venereal disease, kidney stones, asthma, and cancer. In the 1880's, Native Americans used the plant as a contraceptive and snakebite remedy. In Ayurvedic herbal medicine systems the plant is considered diaphoretic, anthelmintic, purgative, and emetic; it is employed in India for stomach tumours, piles, gonorrhoea, intestinal parasites, fever, and warts.

Due to the known toxicity of this plant, it is not recommended as a home herbal remedy. It is best in the hands of knowledgable herbalists and natural health care practitioners.

PLANT CHEMICALS