ABSTRACT
Leucaena is a tropical leguminous tree, Leucaena leucocephala (Lam.) de Wit, that has a startling variety of uses, many of them unexploited. Originating in Latin America, leucaena was spread throughout the tropics and subtropics as a browse legume for its protein-rich foliage. Later its value was recognized as a nurse or shade crop for plantation trees, and as a source of fuelwood, charcoal and roundwood. It became widely naturalized in less acid soils of the low-land tropics, controling erosion and stabilizing forests through its fixation of nitrogen. Its pest resistance and durability under grazing, cutting, fire and drought have become legendary.
Leucaena remains unexploited largely because limited genetic variation of the genus is yet known in agroforestry. The typical leucaenas of the tropics are seedy shrubs. Superior "giant" varieties of leucaena have been collected and bred in the past two decades and deployed widely. Their wood yields are the highest reported for tropical trees. The use of giant leucaenas is increasing as hardwood for charcoal, high-energy fuel, plant support, fence posts, paper pulp, chips for wood products and in reforestation and erosion control. Other new varieties promise expanded use of leucaena as animal forage and dried leaf meal, green manure and fertilizer.
