INFORMATION .LEAFLET
FOREIGN WOODS
Forest Products Laboratory, 1,Forest, Service
U. S. Department of Agriculture
1954
OBECHE
AYOUS
SAMBA
AFRICAN WHITEWOOD
Schum.
Triplochiton sclêroxylon
Family: Sterculiaceae or Triplochitonaceae
By
ELOISE GERRY, Forest Products Technologist
and
CAROL M. MILLER, Scientific Aid
Division of Silvicultural Relations
AUG 31 1954
Other Common Names
srATE
Obeche is known by a considerable number of other names, the most
common of which are starred in the following list (22)._2
...France, Ivory Coast, Germany
Ivory Coast, Gold Coast, French
Cameroons, Nigeria
*African Whitewood.......... United Kingdom
France, Ivory Coast, Nigeria
*Arere...... ...... .....
France,
Ivory Coast, French
*Ayous Cameroons
*Abachi. ............
African (or) bush maple 1
—Maintained
at Madison, Wis. , in cooperation with the University of
Wisconsin.
?Underlined numbers in parentheses refer to the list of numbered references at the end of the report.
( Report) No. 1974
Agriculture-Madison
Ivory Coast
Bamba Ivory Coast
Batobus Ivory Coast
Cofa (Kofa) Nigeria
Egin-fifen Cameroons
Ejuong Nigeria
Ewowo Ivory Coast
Hofa Nigeria
Kpa Cameroons
Nkom
Nigeria, Germany
*Obeche (1) Germany
Obeechi Ivory Coast
Ofa (Ouofa) Nigeria
Okpa (o) . Ivory Coast
Oua-oua Gold Coast
Owawa Gold Coast
Owowa Ivory Coast
Sam..............
Ivory Coast
Sama France,
Ivory Coast
*Samba ... Ivory Coast
Samba-Ayous .........
Ivory Coast
Samkamba Ivory Coast
Sankamba.............
United Kingdom
Satinwood (substitute) .
Ivory Coast
Serama ....Nigeria
Soft Satinwood.........
.... Ivory Coast
Wana...................
Ivory Coast, Gold Coast.
.......
Wawa... ......
Distribution
Obeche is found in most of the countries of West Africa, from French
Guinea to Gaboon (43), especially in Nigeria, the Gold Coast, the Ivory
Coast, and the Cameroons (6, 22, 28, 39, 44, 50).
The Tree
Size and Form
Obeche trees are among the largest forest trees in West Africa and may
attain heights of 150 or more feet and diameters up to 5 or 6 feet above
the buttresses that often extend for some 20 feet up the trunk. Under
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good growth conditions the trees may add 6 feet in height per year.
They frequently form clean, cylindrical boles, free from branches
for a considerable distance above the buttresses and afford exceptional lengths of clear material (19, 22, 26, 39, 43, 44).
The Bark
The thin, soft, smooth and light-colored bark in young obeche trees
makes them conspicuous. As they grow older the bark becomes scaly
and flakes off in patches. The bark has been used locally for roofing
(28, 39, 43).
The Leaves
The shape of obeche leaves suggests those of maple. They are deciduous
and may measure 3 or 4 inches across. They are in alternate arrangement (28, 39).
Flowers and Fruit
The flowers are pinkish or mottled white and red, and fragrant. They
appear after or at the time the old leaves are shed. The pods contain
three rather hard, woody layers surrounding the seeds which are winged
(28, 39).
The Wood
Color
When the trees are freshly felled the wood of obeche is creamy white to
pale yellow in color, with little or no difference in color between the heartwood and the sometimes 4- to 6-inch thick sapwood. The wood weathers
to a light brownish-yellow color (2, 6, 7, 9, 21, 22, 41, 46).
Luster
The luster of obeche wood is described as high and satiny (25, 26, 43).
Report No. 1974
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Odor and Taste
When well-seasoned, obeche is free from odor, but it may have a
disagreeable odor when the tree is first felled. It lacks distinctive
taste (28, 39).
Grain, Texture, and Figure
The grain of obeche may be straight or generally interlocked (13, 44).
The texture is medium to rather coarse, but uniform and rather open.
The wood may present a mild to lustrous stripe or ribbon figure when
quarter sawed (6, 13, 21, 26).
Weight
Obeche is a relatively light wood. When green it may weigh about 35
pounds per cubic foot but when seasoned so that it contains about 10
percent moisture it may weigh about 20 to 25 pounds (13, 22, 39, 44, 45,
46).
Reported specific gravities range from 0. 29 to 0.50 (6, 26, 36). For
wood on the basis of ovendry weight and volume the average is about 0. 30;
at 15 percent moisture content about 0. 40 (26, 43).
Mechanical Properties
Obeche rates as fairly strong, elastic, and resilient considering its
weight (1 3), but it splits rather readily and breaks with a short fracture
(19, 39). Its hardness (43), compared with black walnut as 100 percent,
is 38 (16). It is reported to have about 15 percent less maximum bending
strength than Scotch pine and 50 percent less stiffness (22); however, it
resists blows and vibrations well (13). Table 1 gives the strength properties of obeche as determined by the Forest Products Research Laboratory
of the Department of Scientific and Industrial Research in England and as
presented in Bulletin No. 28, page 39, by F. H. Armstrong. The results
of another series of hardness tests are given in the following tabulation (16).
Report No. 197 4
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Obeche (Ayous) from West Africa
Moisture content (percent) Specific gravity (ovendry wt. vol. ).
Average hardnessi
(Average of 100 tests on 10 pieces) pounds ..... . (Compared to black walnut as 100 percent)
percent.
6. 0
0. 39
&
_ _ .
..
.
475
38
1Load required to embed a 0. 444-inch ball to one-half its
diameter.
Seasoning and Shrinkage
Obeche has been found to air season and kiln dry readily and rather
rapidly (1-inch boards have been kiln dried in a few days without
degrade (46)). The wood has low shrinkage, little tendency to warp or
shake, and good dimensional stability. It is, however, important that
stock be carefully piled to permit good air circulation in order to control discoloration and decay (13, 39, 43, 45, 46).
For kiln drying obeche, the British Forest Products Research Laboratory recommends their Schedule No. 7. The U. S. Forest Products
Laboratory schedule that appears most applicable is T8-C4, as given
in Report No, 1791.
Shrinkage data recorded for obeche dried from the green condition to a
moisture content of 10 percent are: radial 1.7 percent, tangential 2. 2
percent, and general average 1. 9 to 2. 5 (U. S. Bureau of Ships - Code
372aL5 (2465) 1952, and (46) ). This compares favorably with shrinkage
data for sugar pine. Another record of the percentage of shrinkage
occurring from the green to the ovendry condition is: longitudinal 0.15,
radial 2. 49, tangential 5.11, volumetric 7. 84 (16) or 9. 5 (43).
Durability
Obeche is not resistant to decay or insects. It is rich in starch (6),
which fosters dark spots, sapstain, pin worm, and beetle damage (13,
42). In large logs, the heart is often decayed and soft (13). The wood
has not been found very easy to impregnate with preservatives (22, 43).
Discoloration in obeche, due to sap staining fungi, may be prevented
or reduced by water storage or immediate manufacture followed by
Report No. 1974 -5-
storage and seasoning protected as much as possible from rain
and by the use of preservative dipping compounds (22). For storage
and use, relative humidities below 75 percent are important. Staining due to fungi has been observed at 90 percent relative humidity (42).
Incipient decay may be associated with blue stain in discolored logs.
Botryodiplodia theobromae Pat. , a fungus known to cause die-back
and pod-rot in cocoa, has been found in obeche logs. This fungus
reduces toughness, bending strength, stiffness, and specific gravity
of the wood, by attacking the cellulose, pentosans, and lignin in a way
that is similar to the action of a white-rot fungus (14, 39, 46).
Working Characteristics
Because it is comparatively soft and uniform, obeche wood is easy to
work with either hand or machine tools (6, 13, 22, 26). It contains no
gums, oils, or resins to interfere with cutting, staining or painting (39).
Sharp, thin-edged tools are desirable, however, and a cutting angle of
35° to 38° has been found helpful for avoiding any "picking-up" or
crumbling of the surface of the wood (22). For staining and finishing,
little filler is required. Obeche veneers and glues well and takes nails
and screws without undue splitting, but fasteners do not hold particularly
well under rough usage (5, 6, 22, 39).
Uses
The use of obeche has steadily increased (22) so that it ranks as an
important and increasingly imported species (43). Locally it is used for
dugout canoes, but it has wide application in interior joinery, framing,
furniture, shop fittings, veneer (as a substitute for yellow-poplar), core
stock for plywood (46), vehicle bodies, laundry appliances, boxes,
furriers nailing boards, and pattern stock (under test by Philadelphia
Naval Shipyard, Bureau of Ships in 1952) because of its low shrinkage
(6, 13, 19, 22, 39). It has sometimes been used as a substitute for
satinwood and for primavera but is considered inferior. When stained,
it has also been substituted for mahogany (26).
Supplies
Ordinarily supplies of obeche in good widths and lengths and free from
knots have been plentiful (22, 46). The wood has been exported in considerable volume from Nigeria, and the Gold Coast, and to a lesser
extent from the Ivory Coast and the French Cameroons (13, 22).
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It may be shipped in the log form, or squared, or as lumber. It
ranks as an increasingly important export wood (43).
Structure
Growth rings. --Growth rings are present but rather indistinct. The
boundaries are due chiefly to slight differences in density (21, 24, 39,
43, 46).
Pores. --The comparatively few, rather large pores are diffusely
scattered, usually open, mostly solitary, but sometimes in radial pairs
or groups; tyloses may be present but have not been found to be abundant
(19, 21, 24, 39, 46).
Rays. --The rays are faintly visible without magnification on cross sections and in tangential surfaces and are distinct but not conspicuous on
the radial surface. Ripple marks are present and fairly distinct under
a lens (25).
Parenchyma. --Parenchyma is abundant round the pores and in fine lines,
barely visible under magnification (25).
Fibers. --Fibers are short and storied. They are of a special, relatively nonelongated type frequently found in very soft woods (9, 21, 40).
Report No. 1974
-7-
References
1.
Anonymous
1929. Nos bois coloniaux (C8te d' Ivoire et Cameroun).
Schum)
Samba - Ayous (Triplochiton scleroxylon
Publ. by Assn. Colonies-Sciences & Comite Natl. des
Bois Coloniaux, Paris, pp. 4, 2 plates. (Trop. Woods
19: 68).
(A concise account of this species from both the scientific and commercial aspects. )
2.
1936. Three Nigerian Timbers
(Reprinted from Wood (London) Dec. 1936.) Issued by
the Office of the Chief Conservator of Forests, Nigeria.
Pp. 8. (Trop. Woods 53:61)
3.
1938. Gold Coast Timbers.
Published in connection with the Gold Coast exhibit at the
Empire Exhibition at Glasgow, Scotland, 1938. Pp. 27;
7 x 10; 11 colored plates, 1 map. (Trop. Woods 56: 32)
4.
1939. I. Abachi, Triplochiton scleroxylon K. Schum.
(Sterculiaceae) Merkblatter fiber Koloniale NutzhOlzer.
Inst. f. ausland. und. Kol. Forstw. der Forstlichen
Hochschule No. 1, p. 8, Tharandt. (Forestry Absts.
1(3): 168, 1940. Trop. Woods No. 60: 61, 1939)
(Leaflets on vernacular and trade names, range, occurrence, form of tree, anatomy, properties, and utilization. )
5.
1945. Empire Timbers. Forest Products Research.
Pub. by His Majesty's Stationery Office, London, pp. 75-76.
6.
1949. Nos Bois Tropicaux-Ayous, p. 16.
Plaquette Documentaire Editee sous les auspices du Comite
National des Bois Tropicaux. Paris.
7. Ainslie, J. R.
1938. In the forests of Nigeria. Supplement (in color) to Wood
(British) (describes Empire Exhibit, Glasgow). May Nema
Press, London.
Report No 1974
-8
8.
Aubreville, A.
1928. Notes sur le Samba (Triplochiton scleroxylon).
Bull. Mensuel de PAgence Economique de l'Afrique
Occidentale Fran5aise, Feb. , Vol. 9, No. 86, pp. 5052. Paris.
9.
Boulton, E. H. B. and Price,T. J.
1931. Some Further Notes on Triplochiton scleroxylon.
Trop. Woods March 1, No. 25, pp. 3-4. Yale Univ.
School of Forestry, New Haven, Conn.
10.
Chevalier, A.
1909. Le bois de la Cote d'
Paris.
11.
1917. La fork et les bois du Gabon. Paris.
12.
Chipp, T. F.
1922. The Forest Officers' Handbook of the Gold Coast, Ashanti,
and the Northern Territories. London.
13.
Cox, H. A.
1949. Wood Specimens, 100 reproductions in color.
The Nema Press, Proprietors of "Wood" London.
(Same article in "Wood" Vol. 1, No. 12, pp. 553-554
(No. 12) Dec. 1936)
14.
Findlay, W. P. K. and Pettifor, C. B.
1939. Effect of blue stain on the strength of obeche (Triplochiton
scleroxylon).
Empire Forestry Jour. Vol. 18, No. 2, pp. 259-267.
15.
Foggie, A.
1947. Some ecological observations on a tropical forest type in
the Gold Coast. Jour. Ecology Vol. 34, No. 1, pp. 88106. 5 figs. Feb.
(Trop. Woods No. 91, p. 62, New Haven, Conn. )
16.
Harrar, Ellwood S.
1941-42. Some physical Properties of Modern Cabinet Woods.
1. Hardness; II. Screw-holding Power; III. Directional
and Volume Shrinkage. Trop. Woods No. 68, p. 4; No.
70, p. 5; No. 71, p. 27, Dec. 1941, June and September
1942. Yale Univ. School of Forestry, New Haven, Conn.
Report No. 1974
-9-
17.
Hedin, L.
1929. Sur quelque Essence Forestieres Exploitees au Cameroun.
Rev. Bot. Appl. & dl Agro Tropicale Vol. 9, No. 89,
pp. 39-51, January. Paris.
Trop. Woods No, 20, p. 47.
18.
Holland, J. H.
1922. The Useful Plants of Nigeria. Bull. Misc. Inf. Kew, add.
ser. lx; pp. 104-105. London.
19.
Howard, A. L.
1948. Timbers of the World. 3rd. ed. p. 428.
Macmillan & Co. , Ltd. , London and New York.
20.
Hutchinson, J. and Dalziel, J. M.
1928. Flora of West Tropical Africa. Vol. I, pt. 2, p. 248.
London.
21.
Jane, Frank W.
1951. The Structure of Timbers of the World -- Triplochiton.
Timber News Vol. 59, No. 2149, November.
22.
Jay, B. Alwyn.
1950. Timbers of West Africa. (Red Book Series, 3rd. ed. )
Pp. 63-65. Timber Dev. Asso. Ltd., London.
23.
Jentsch, F. and Appel, E.
1937. Beschreibung tropischer Holzer aus dem Urwalde
Kameruns. Zeitschrift fur Weltforstwirtschaft Vol. 3,
pp. 110-120; 235-246; 331-341; 497-506. 72 figs.
Neudamm & Berlin. (Trop. Woods No. 50, p. 53)
24.
Johnston, D. R.
1951. Obeche (Structure).
Wood (Brit.) Vol. 16, No. 9, p. 349, sheet 3, Sept.
Nema Press, London.
25.
Kribs, D. A.
1950. Commercial Foreign Woods on the American Market.
Pp. 139-140 (illus). Forest School, State College, Pa.
26.
Lamb, George N.
1948. Foreign Woods: Origin, Use, Properties and Nomenclature: Obeche. Wood Products, Vol. 53, No. 4, p. 24,
April. Chicago.
Report No. 1974
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27.
Martineau
1930. ttude sur le Temperament des Principales Essences de
la Cote d'Ivoire. Actes et Comptes Rendus de P Assoc.
Colonies-Sciences Vol. 6, No. 56, pp. 30-35, Feb.
Paris. (Trop. Woods No. 22, p. 47)
28.
Mell, C. D.
1930. The Ayous or the Satinwood of West Africa. Veneers
Vol. 24, No. 2, pp. 21-22, Feb. Indianapolis, Ind.
29.
Meniaud, Jean
1922. La foret de la COted'Ivoire et son exploitation. P. 29,
Paris.
30.
et Bretonnet, Frederic
1926. Les Bois Coloniaux d'Afrique dans l' Industrie. Melun.
31.
Metcalfe, C. R. and Chalk, L.
1950. Anatomy of the Dicotyledons, Vol. 1, pp. 249-254 (refs.)
Clarendon Press, Oxford, England.
32.
Meyer, Hans
1933. Buch der Holznamen. (Book of Wood Names)
N. & H. Schaefer, Hanover, Germany.
33.
Monnin, M. M. et Collardet, J.
1930. Etude Physique et Mecanique de Bois Coloniaux, pp. 34,
89, table A I. Assoc. Colonies-Sciences et Corn. Natl.
de Bois Coloniaux, Paris.
34.
Muller, J. F. & Son
19278. Jahresbericht fiber Nutheilzer. Hamburg.
35.
Normand, D.
1943. La Denomination Officielle des Principaux Bois Coloniaux
Fran5aise. Rev. Bot. App. grdl Agr. Tropical 23, pp.
160-164.
(Trop. Woods No. 91, p. 57)
36.
Organization for European Economic Cooperation (OEEC)
1951. African Tropical Timber, pp. 54, 55, 314, 315, 354, 355.
Paris.
37.
Perrot, Emile
1921. Le bois de la cite d' Ivoire. I. Paris.
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38.
Prain, D.
1905. Mansonieae, a new tribe of the natural order
Sterculiaceae. Jour. Linnean Soc. (Botany) Vol.
37, pp. 250-263. London.
39.
Record, Samuel J.
1929. The West African Abachi, Ayous, or Samba
(Triplochiton scleroxylon). Trop. Woods No. 18,
pp. 43-54, June 1. Yale Univ. School of Forestry,
New Haven, Conn.
40.
and Mell, C. D.
1924. Timbers of Tropical America. Pp. 285-286. Yale
Press, New Haven, Conn.
41.
Roddis Plywood Corporation
1950. Characteristics of Modern Woods.
3rd ed. , p. 7. Marshfield, Wis.
42.
Savory, J. G.
1953. Surface Moulds in Obeche.
Timber Tech. Vol. 61, No. 2164, pp. 81-83. Illus.
Feb. London.
43.
Schmidt, E.
Schum.) (Familie
1951. Abachi (Triplochiton scleroxylon Sterculiaceae. Nr. 28) OberseehOlzer, Beipage der
Zeitschrift ftir Weltforstivirtschaft Band 14, Heft 5,
Illus. a Color plate and photomicrographs. Fritz Haller
Verlag. Berlin-Grunewald.
44.
Scott, M. H.
1943. Some West African substitutes for well known timbers.
Journ. So. Afr. For. Assoc. (Pretoria), No. 10, pp.
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45.
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Pretoria.
46.
1950. Notes on the More Important African Timbers Imported
into the Union with Special Reference to Portuguese East
African Species.
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Illus. Pretoria.
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47.
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1908. Systematic anatomy of the Dicotyledons.
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48.
Stebbing, E. P.
1937. The Forests of West Africa and the Sahara, pp. 149-150.
W. & R. Chambers, Ltd. London.
49.
Stone, Herbert and Cox, H. A.
1922. A guide to the identification of the more useful timbers
of Nigeria. Pp. 19-21. Nigeria.
50.
Unwin, A. Harold
1920. West African Forests and Forestry.
Pp. 87, 417, 436. T. Fisher Unwin Ltd. London.
Report No. 1974
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1
Table 1. --Strength properties of Nigerian obecheGreen
Property
Moisture content .......... ....... .percent: :
W
eightper cubic foot ................. lbs •
12
76
•▪
°
Static bending (center loading)
Maximum bending strength.. lb. per sq. in. : 5, 100 :
Stiffness (modulus of elas-
700
ticity). . . . . ...... . . 1, 000 lb. per sq. in. :
:
Energy consumed in bending
6.2
o maximum load.. in. -lb. per cu. in. :
T
:
To total fracture (total
14.0
work). . . . . .... . . in. -lb. per cu. in..
Impact
Resistance to suddenly applied loads
Maximum drop of 50 lb. hammer... in.:
: Air dry
23
:
: 7, 500
:
850
:
.
:
6.9
:
10. 9
24
19
Compression
Maximum compressive strength
Parallel to grain ..... ...lb. per sq. in. : 2, 580
: 3, 940
Hardness -- ball test
Resistance to indentation
On side grain.... .
On end grain.. .......
•
.......... lb..
...... lb..
420
460
:
:
430
690
Shear
Maximum shearing strength
Parallel to grain .....
.1b. per sq. in. :
670
:
990
Cleavage
Resistance to splitting
In radial plane ...... lb. per in. width: In tangential plane... lb. per in. width:
200
170
:
:
230
210
1
—Reported by F. H. Armstrong in the 1953 Forest Products Research
Bulletin No. 28, page 39.
Report No. 1974