Rattail

Appearance

This plant is a perennial herb or shrub growing up to 2 or 2.5 meters tall. It has an upright, branching stem, sometimes with a woody base. The leaves are oppositely arranged. The blades are up to 8 to 10 centimeters long, oval in shape with sharply toothed edges, and rough-textured or wrinkly on the upper surfaces.

The inflorescence is a very narrow spike up to 40 to 45 centimeters long covered in pointed bracts. Occasional flower corollas bloom from between the bracts. The flowers are deep purple-blue to lavender with pale centers, and white-flowered plants are known. The flowers last a single day before wilting. The plant was named for Cayenne, the capital of French Guiana.

Distribution

It is known in many other parts of the world as an introduced species, including regions in Africa, India, Indonesia, Australia, Florida in the United States, and many Pacific Islands. Its distribution is now considered pantropical. In many places, such as New Caledonia, it has become an invasive species.

Cultural

This plant has some uses in traditional medicine. Several Latin American peoples recognize extracts of the plant as a treatment to ease the symptoms of malaria. The boiled juice or a tea made from the leaves or the whole plant is taken to relieve fever and other symptoms. It is also used for dysentery, pain, and liver disorders. A tea of the leaves is taken to help control diabetes in Peru and other areas. Laboratory tests indicate that the plant has anti-inflammatory properties.