River Tamarind
Leucaena leucocephala

ECOLOGY
This species is invasive in tropical regions. In its own origin, it is an important forage plant and habitat for birds.

ETHNOBOTANY
Its main use is as fodder for animals. Its leaves are very digestible and nutritious for ruminant animals, rivaling or exceeding alfalfa in nutritive value, and can be eaten mature or immature, grazed or harvested, fresh or dried. Young pods and seeds have been eaten raw for centuries by indigenous tribes in Mexico and Central America, although the presence of mimosine limits their consumption. However, cooking the pods, ripe or immature, removes much of the mimosine and allows them to be consumed as a vegetable. Ripe seeds are parched and eaten as a snack like popcorn or ground and used as a substitute for coffee. Seedpods and young shoots are used in a variety of dishes in Asian cuisine. The wood of the plant is used as firewood and to make posts, furniture, flooring, wood pulp, particle board, and charcoal. The gum is sometimes used as a substitute for gum arabic. Red, brown and black dyes can be obtained from the pods, leaves and bark. The plant has been used in folk medicine a variety of purposes. The bark is taken to relieve internal pain. An infusion of the bark and root have been used as an emetic, contraceptive, emmenagogue, ecbolic, abortifacient or depilatory. The bark and root can also be used topically to eliminate lice and flea infestations. The plant has been used as a purgative, vermifuge, or emollient.

NATURAL DISTRIBUTION
Native to southern Mexico, this species was spread by colonizers (especially the Spanish) as a plant for animal fodder, wind breaks for ranches, and for erosion control. In many places this species is now considered a noxious weed. Though it is weedy in the landscapes of our region, it does not escape into the wild very often.

TAXONOMY AND NAME
This plant is in the Fabaceae, the legume family. There are 25 species of Leucaena native to the Americas, ranging from Texas in the United States south to Peru..
The original Nahuatl word for the plant, huaxin, still survives today in the Spanish name for the plant, guaje, and in the name of the Mexican state Oaxaca, which reportedly means “place where the leucaena grows”. The genus name, Leucaena, appears to derive from the Greek verb leukainein and means “to become white,” perhaps referring to the plant’s appearance when in flower. The specific name leucocephala comes from two Greek words, leukos, meaning “white,” and cephale, meaning “head,” referring to the plant’s flowers.