Imbuia typically refers to commercial lumbers derived from Brazilian walnut trees, but also refers to the trees, themselves, as well. Known by either of the binomial names Ocotea porosa or Phoebe porosa, the trees are native to subtropical areas in southern Brazil. Common names and variations in spelling include "imbuia," "imbuya," "embuia," "embuya," and simply, Brazilian walnut. Although commonly referred to as a walnut tree, Ocotea porosa shares no scientific similarities with trees in the walnut family and produces no nuts.
Mature trees reach heights of up to 130 feet (39.6 m) with trunks as large as 6 feet (1.83 m) in diameter. Leaves are long, narrow, and slightly pointed, with a mild to bright green color. Flowers are small, yellow and slightly trumpet shaped. The main trunk of the Ocotea porosa often forks close to ground level, producing a divided appearance at maturity. Large globular growths on the trunk, known as pouches, are common.
As a highly prized species of Brazilian walnut, imbuia grows naturally in large groupings, known as stands, near the Araucaria forest region of southern Brazil. Other states in Brazil, including Rio de Janeiro and Sao Paulo, host small or limited native stands of imbuia trees. Some forestry professionals suggest that additional native stands may also exist in Argentina and Paraguay, although reports are unverified. Considered a threatened species in its native rain forest habitat, this particular variety of tree favors altitudes between 2,000 feet (609.6 m) and 4,000 feet (1219.2 m).
While native stands are considered threatened or vulnerable, there is considerable commercial demand for the choice lumber. Featured in a variety of high end products, from cabinetry to furniture, artistic sculptures to gunstocks, imbuia is most often milled for veneers, plank flooring, joinery, and other decorative woodwork. When milled, the lumber finish is considered fine, with medium to high luster. Colors range from a yellow-olive to a dark, chocolate brown, with a striking variegated grain.
Heartwood imbuia lumber has a natural resistance to certain fungi that speed wood decay. Likewise, imbuia lumber is naturally resistant to certain burrowers and termites. Paneling and other wood products made from imbuia typically require little, if any, chemical treatment, varnish, or other preservatives. The freshly milled lumber has a strong, yet appealing, spicy aroma, although the scent dissipates as the drying process continues.
Demand for imbuia lumber products, in spite of the tree's threatened status, has helped encourage its popularity as both a commercial nursery product and a horticultural tree for domestic settings. Although native to rain forests, imbuia is suitable for subtropical climates and other moisture-rich habitats. Conservation efforts in Brazil seek to protect select native localities in an effort to counteract timber exploitation and give slow-growing native stands an opportunity to recover.