CUMARU - SHIHUAHUACO (PERÚ)
TECHNICAL CARD
| Species : | Dipteryx micrantha Harms |
| Family : | Fabace - papilionoideae |
| Synonym : | Coumarouna micrantha (Harms) Kucke |
| Commun Names : | Perú: shihuahuaco, charapilla, kumarut, Bolivia: coumarou. Brasil: cumaru. Colombia: charapilla. Venezuela: sarropia. |
| International Business Name : | Cumaru |
CHARACTERISTICS OF THE SPECIES
Geographical distribution: the distribution of the species was obtained from literature and herbal reports within the provinces of Loreto and Ucayali . Average to large amounts of the species can be found in the Northern Amazon of Peru .
The tree: 40 m. (131 feet) tall, 100 cm (3,28 feet) diameter. Steep visible roots, 4 m (13,1 feet) high, 1,5 m (4,92 feet) thick; sometimes in young trees, visible roots thinly extend up the trunk, making it seem corrugated and depicting longitudinal concavity and convexity. In old trees, trunk is round. Large, parasol-like top. The surface of the bark is smooth, grayish brown to yellowish brown. Woody dead bark comes apart in irregular 1 cm (0.39 inch) thick sheets which are cork-like inside. When apart, they leave round, bas-relieved, orange brown traces that resemble hammering. Main bark is made up of two 2mm thick layers.
CHARACTERISTICS OF THE WOOD
Color: When freshly cut, sapwood (alburnum) is white and hardwood (duramen) is brown, lightly. Great and abrupt contrast of colors between both layers. When dried in open air, laburnum turns pinkish white HUE 8/2 7.5 YR and duramen turns reddish brown HUE 5/4 YR. (Munsell Soil Color Charts).
| Fragrance: | Distinctive and characteristic |
| Shine or gloss: | Moderate to high |
| Grain: | Interbred |
| Texture: | Medium |
| Streaks or patterns: | Clearly-defined, Overlapped arcs. Narrow, parallel, glossy bnads streaked in yellow in the tangential area. |
TECHNICAL CHARACTERISTICS
Physical Properties
| Primary density : | 0,87 gr/cm3 |
| Tangencial contraction : | 9,10 % |
| Radial contraction : | 5,50 % |
| Volumetric contraction : | 15,00 % |
| T/R Ratio : | 1,60 |
Mechanical Properties
| Module of elasticity in flexion : | 153000 kg/cm2 |
| Module of breakage in flexion : | 1 286 kg/cm2 |
| Parallel compression (RM) : | 672 kg/cm2 |
| Perpendicular compression (ELP) : | 150 kg/cm2 |
| Grain-parallel cut : | 145 kg/cm2 |
| Hardness on the sides : | 1353 kg/cm2 |
| Firmness (Resistence to impact) : | 620 kg - m |
TECHNICAL ADVICE
Shihuahuaco is a heavy type of Wood, showing low linear shrinkage and stable volumetric shrinkage.
Mechanincal resistance is ranked as high. Wood is more difficult than normal to saw due to its hardness and interbred grain; therefore, adequate tools and star shaped chain saws should be used.
Large pieces are difficult to dry naturally, warping might occur. Performs well when artificially dried in amild, 10-day program for small 13-mm-thick pieces. Well resistence at biological attack. No need to be preserved.
USES
Hardwood for sleepers, bridges over gorges of small riverbed, floors, heavy construction, decking, mortise and tenon joints and parquet
