USDA Forest Service
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53705-2398
Wood Technical Fact Sheet
Other Common Names: Hierba mala, Mago (Mexico), Olivo (Panama), Palo de leche, Caucho (Colombia), Lechero (Venezuela), Pau de leite, Tapuru (Brazil), Caucho- mashan (Peru), Curupi, Lecheron (Argentina).
Distribution: Throughout tropical America from Mexico and the West Indies to Uruguay and Argentina.
The Tree: May attain heights of 90 to 115 ft with a well-formed trunk sometimes 36 in. in diameter. In some species, the inner bark contains a poisonous latex.
General Characteristics: Heartwood whitish, yellowish, or light brown, not distinct from the cream-colored sapwood. Grain is straight to slightly interlocked; luster low; texture medium; without distinctive odor or taste.
Weight: Basic specific gravity (ovendry weight/green volume) 0.47; air-dry density 36 pcf.
Mechanical Properties: (First two sets of data based on the 2-in. standard, the third on the 1-in. standard.)
Moisture content Bending strength Modulus of elasticity Maximum crushing strength
(%) (Psi) (1,000 psi) (Psi)
Green (73) 7,700 1,480 3,200
12% 10,790 1,680 6,120
12% (44) 12,000 2,140 NA
12% (41) 11,900 NA 6,150
Janka side hardness 520 lb for green material and 700 lb for dry. Forest Products Laboratory toughness average for green and dry material 84 in.-lb (5/8-in. specimen).
Drying and Shrinkage: The wood is reported to air-dry rapidly with only slight warping and checking. No data available on kiln schedules. Shrinkage green to ovendry: radial 3.3%; tangential 6.6%; volumetric 9.2%.
Working Properties: The wood works easily because of its low density; sometimes surfaces are fuzzy but generally machines smoothly. One report indicates difficulty in sanding.
Durability: The wood has low resistance to decay and insect attack, including dry-wood termites. Lumber is particularly prone to blue stain.
Preservation: Both heartwood and sapwood are easy to treat; high absorptions and complete penetration are obtained using either pressure-vacuum or open-tank systems.
Uses: Plywood, fiberboard, particleboard, general carpentry, millwork, utility furniture, boxes and crates.
Additional Reading: (41), (44), (73)