Dipteryx odorata

Syn.  Coumarouna odorata

Family: Apocynaceae

Tonka

Ebo

 

Other Common Names: Almendro (Costa Rica, Panama), Sarrapia (Venezuela, Colombia), Cumaru (Brazil), Charapilla, Cumarut (Peru).

 

Distribution: The Guianas, Venezuela, Colombia, and the Amazon region of Brazil; reaches its best development on well-drained gravelly or sandy sites.  Cultivated in many areas for the tonka beans used as a flavoring.

 

The Tree: A large overstory tree sometimes to 160 ft in height and trunk diameters to 40 in.; unbuttressed cylindrical boles are generally clear to 60 to 80 ft.

 

The Wood:

General Characteristics: Fresh heartwood is reddish brown or purplish brown with light yellowish-brown or purplish streaks; upon exposure gradually' becomes uniform light brown or yellowish brown.  Sapwood is distinct, narrow, yellowish brown. Luster rather low to medium; texture fine; grain interlocked; waxy or oily feel; taste not distinctive but may have a vanilla-like or rancid odor.

 

Weight: Basic specific gravity (ovendry weight/green volume) ranges from 0.80 to 0.91; air-dry density 62 to 81 pcf.

 

Mechanical Properties: (First set of values based on 2-in.  standard; second set on 1-in.  standard.)

 

 

 

 

 

Moisture content   Bending strength   Modulus of elasticity   Maximum crushing strength

            (%)                  (Psi)                            (1,000 psi)                   (Psi)

Green (74)                   19,290                         2,690                           9,020

12%                             27,270                         3,030                         13,720

 

12% (24)                     22,400                         3,010                         13,200

 

Janka side hardness 2,200 lb for green material and 3,540 lb at 12% moisture content. Forest Products Laboratory toughness average for green and dry material is 265 in.-lb. (5/8-in.  specimen).

 

Drying and Shrinkage: The wood is rated as easy to air-season with a slight tendency to check and with moderate warping; drying was uniformly rapid.  No dry kiln data available.  Shrinkage from green to ovendry: radial 5.0%; tangential 7.6%; volumetric 12.0%.

 

Working Properties: The wood is difficult to saw and bore; where severely interlocked grain is not present, the wood planes to a smooth surface.  Because of its high density and oily nature, the wood glues poorly.

 

Durability: The timbers have a reputation for being very durable.  Laboratory tests also show the heartwood to be very durable in resistance to both brown-rot and white rot fungi.  The wood has excellent weathering characteristics.

 

Preservation: Heartwood absorption and penetration of treating solutions using both open-tank and pressure-vacuum systems are inadequate.  Sapwood is reported to treat well, particularly with a high end-grain exposure.

 

Uses: Heavy construction, cogs and shafts, barge and dock fenders, flooring, railroad crossties, pulp mill equipment, tool handles, bearings, turnery.  A substitute for lignum vitae.

 

Additional Reading: (24), (46), (56), (74)

 

24.  Food and Agriculture Organization.  1970.  Estudio de preinversion para el desarrollo             forestal de la    Guyana Venezolana.  lnforme final.  Tomo III.  Las madera del area             del proyecto.  FAO Report FAO/SF: 82 VEN 5. Rome.

46.  Longwood, F. R. 1962.  Present and potential commercial timbers of the Caribbean.              Agriculture Handbook No.  207.  U.S.  Department of Agriculture.

56.  Record, S. J., and R. W. Hess.  1949.  Timbers of the new world.  Yale University             Press, New Haven, Conn.

74.  Wangaard, F. F., and A. F. Muschler.  1952.  Properties and uses of tropical woods,             III.  Tropical Woods 98:1-190.

 

From: Chudnoff, Martin. 1984. Tropical Timbers of the World. USDA Forest Service. Ag. Handbook No. 607.