Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53705-2398
Wood Technical Fact Sheet
Arariba Porcupine Wood
Other Common Names: Amarillo guayaquil (Panama, Ecuador), Guayacan hobo, Balaustre
(Colombia, Venezuela), Ararauba, Ararauva (Brazil), Morosimo (Paraguay).
Distribution: Five or six species of rather infrequent occurrence from Panama to Ecuador and southern Brazil.
The Tree: A medium-sized to large well-formed tree; generally up to 100 ft high with diameters of 30 to 50 in.; commonly to heights of 40 ft and diameters to 16 in. Narrow buttresses to heights of 3 ft in some species.
General Characteristics: Heartwood yellow or orange, typically variegated, sometimes "rainbow hued," usually changing to red or brown; rather sharply demarcated from the yellowish sapwood. Luster medium to high; texture fine to rather coarse; grain straight to irregular; some species without odor or taste, others with distinctive odor and sometimes with perceptive taste.
Weight: Basic specific gravity (ovendry weight/green volume) varies with species from 0.61 to 0.69; air-dry density 46 to 53 pcf.
Mechanical Properties: (First set of data based on 2-cm standard, second set on 1-i
standard, and third on 2-in. standard.)
Moisture content Bending strength Modulus of elasticity Maximum crushing strength
(%) (Psi) (1,000 psi) (Psi)
Green (30) 14,200 1,500 5,900
15% 16,800 NA 7,900
12% (24) 18,600 2,130 9,550
12% (44) 17,200 2,440 NA
Janka side hardness 1,030 lb for dry wood. Amsler toughness 288 in.-lb at 15% moisture content (2-cm specimen).
Drying and Shrinkage: Reported to have a moderate drying rate with little to no warp or checking. Kiln schedule T6-D2 is suggested for 4/4 stock of C. ochroxylon and T3-D1 for 8/4. Shrinkage green to ovendry: radial 2.4%; tangential 5.6%; volumetric 8.4%.
Working Properties: The wood is easy to machine with all tools; finishing very smoothly but there may be some fuzzy grain on planing of radial surfaces.
Durability: The wood is reported to be highly resistant to attack by decay fungi, termites and other insects, and marine borers (Teredo).
Preservation: impregnation with wood preservatives is only moderate using pressure-vacuum systems, absorption and penetration is negligible using the open-tank method.
Uses: Heavy construction, railroad crossties, fine furniture and cabinet work, flooring, ship components (planking, keel, decking, and trim), turnery, decorative veneers, cooperage.
Additional Reading: (24), (30), (44), (56)