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Clicking any heading in the main data area (at right) will scroll the page back to this top position. Use the following links to jump to the associated section in the main data. Blunting Effect Boring Comments Common Names Common Uses Countries of Distribution Cutting Resistance Distribution Overview Drying Defects Ease of Drying Environmental Profile Family Name Gluing Grain Heartwood Color Kiln Drying Rate Luster Nailing Natural Durability Numerical Data Odor Planing Polishing Product Sources References Regions of Distribution Resin Content Resistance to Impregnation Response to Hand Tools Sanding Sapwood Color Scientific Name Screwing Silica Content Strength Properties Texture Toxicity Trade Name Tree Identification Tree Size Scientific Name Lannea welwitschii Trade Name Kumbi Family Name Anacardiaceae Common Names Abala puli, Abalapuli, Aberewa nyansid, Acajou magona, Asogedaka, Awpaw, Bopire, Borepore, Duko, Durgo, Duroko, Ekika, Ekika aja, Ekikaja, Eknalokpoe, Ekoa, Ekoe, Ewinwan, Kakoro, Kala, Kumbi, Kumenini, Kuntunkuni, Lannea, Leko, Loloti, Ngolo ngoloti, Oyinyin, Purukuma, Tchiko, Tyetebu Regions of Distribution Africa Countries of Distribution  [VIEW MAP] Angola, Cameroon, Congo, Gabon, Ghana, Ivory Coast, Liberia, Nigeria, Uganda, Zaire Common Uses Balusters, Bedroom suites, Boxes and crates, Building construction, Building materials, Cabinetmaking, Canoes, Casks, Chairs, Chemical derivatives, Chests, Concealed parts (Furniture), Construction, Core Stock, Decorative plywood, Desks, Dining-room furniture, Domestic flooring, Dowell pins, Dowells, Drawer sides, Excelsior, Factory flooring, Fine furniture, Floor lamps, Flooring, Fuelwood, Furniture , Furniture components, Furniture squares or stock, Hardboards, Hatracks, Interior construction, Interior trim, Joinery, Kitchen cabinets, Light construction, Living-room suites, Matchboxes, Matches, Millwork, Moldings, Office furniture, Packing cases, Parquet flooring, Particleboard, Plywood, Pulp/Paper products Environmental Profile Secure in many areas of its range Little threat to its survival, at least in the immediate future Data source is World Conservation Monitoring Center Distribution Overview West and Central Africa (mainly in Ivory Coast, Ghana, Cameroon, and Zaire). Heartwood Color Pale red to pink Yellow to golden-yellow to orange White to cream Red - pale Pink-Gray Pale brown Greenish to greyish A silvery luster or brown veining is sometimes present. Sapwood Color White to yellow Color not distinct from heartwood Grain Straight Even Interlocked Straight Occasionally interlocked, but not always Quartersawn surfaces exhibit a ribbon-like, striped or mottled figure. Texture Fine Medium Fine to medium Even textured Luster Silvery luster Natural Durability Resistant to marine borers Non durable Susceptible to attack from termites (Isoptera) Susceptible to marine borer attack Susceptible to attack from powder post (Lyctid & Bostrychid) beetles Susceptible to attack by marine borers and termites Sapwood is susceptible to wood staining fungal attack Perishable Logs should be converted as soon as possible, to prevent losses due to blue stain and pinhole borer attack Odor Tasteless Distinctive resinous odor Silica Content He wood contains silica which tends to interfere with some machining operations. Resin Content Contains numerous resin canals which contain a brownish-yellow substance. Toxicity Sawdust from machining operations has been reported to cause dermatitis, nose, and throat irritation in some individuals. Drying Defects Distortion Splitting Checking Slight tendency for the wood to warp and check. Shrinkage in the radial and tangential directions are medium Ease of Drying Fairly Easy Rapidly Veneer dries relatively rapidly, with little degrade except slight tendency to split Fairly easy Kiln Drying Rate Naturally dries quickly Tree Identification Bole/stem form is not buttressed Bole/stem form is buttressed Bole/stem form is straight Bole/stem form is cylindrical Tree Size Tree height is 10-20 m Trunk diameter is 150-200 cm Product Sources The ITTO reports that timber from this species is produced and exported in negligible quantities. Comments Fairly stiff General finishing qualities are rated as good Moderately resiliant Pliable Soft Blunting Effect Little Severe blunting effect on cutting tools due to high silica content Boring Fair to good results Fairly easy to very easy Cutting Resistance Fairly Difficult to Very Difficult to saw Moderate to saw Cutting Resistance with dry wood is difficult Larger sized material is hard to saw. Silica in the wood may cause saws to overheat and bind up. Gluing Very good properties Nailing Holds nails well Good nailing properties Easy to nail Planing Very Good to Excellent Results Fairly Difficult to Very Difficult Fairly Easy to Very Easy Fair to Good Results Easy to plane Planed surfaces may be woolly, but smooth surfaces can be obtained with some care. The material responds well to ordinary tools in most woodworking operations, including turning, boring, moulding, mortising, and routing. Resistance to Impregnation Sapwood is moderately resistant Heartwood is resistant Response to Hand Tools Fairly Difficult to Difficult to Work Easy to Work Easy to machine The timber has a fairly good response to hand tools. Sanding Although there is a tendency for surfaces to be fuzzy, a good finish can be obtained with care Screwing Good screwing properties Good screw holding properties Polishing Good results Strength Properties Bending strength (MOR) = medium Max. crushing strength = medium Hardness (side grain) = very soft Density (dry weight) = 38-45 lbs/cu. ft. Density (dry weight) = 31-37 lbs/cu. ft. Density (dry weight) = 23-30 lbs/cu. ft. Bending strength (MOR) = low Shrinkage, Volumetric = moderate Shrinkage, Volumetric = fairly large Modulus of Elasticity (stiffness) = low Numerical Data Item Green Dry English Bending Strength 7956 12335 psi Density 29 lbs/ft3 Hardness 319 lbs Maximum Crushing Strength 3873 6614 psi Shearing Strength 1666 psi Stiffness 1353 1575 1000 psi Weight 35 28 lbs/ft3 Volumetric Shrinkage 12 % Item Green Dry Metric Bending Strength 559 867 kg/cm2 Density 464 kg/m3 Hardness 144 kg Maximum Crushing Strength 272 465 kg/cm2 Shearing Strength 117 kg/cm2 Stiffness 95 110 1000 kg/cm2 Weight 560 448 kg/m3 References Bolza, E., Keating, W.G.,1972,African Timbers - the Properties, Uses and Characteristics of 700 Species,C.S.I.R.O. Div. of Building Research Eggeling, W.J.,1940,Indigenous Trees of Uganda,Govt. Printer Entebbe Uganda Erfurth, T., Rusche, H.,1976,The Marketing of Tropical Wood A. Wood Species from African Moist Forests,F.A.O. Forestry Department Fouarge, J., Gerard, G.,1964,Bois du Mayumbe,I.N.E.A.C. Belguim Hedin, L.,1930,Etude sur la Foret et les Bois du Cameroun,Haut-Commissaire de la Cameroun Irvine, F.R.,1961,Woody Plants of Ghana,O.U.P. London ITTO. 1986. Tropical Timber Atlas, Volume 1 - Africa. International Tropical Timber Organization (ITTO) and Centre Technique Forestier Tropical (CTFT, 45bis, Avenue de la Belle Gabrielle, Nogent-sur-Marne Cedex, France. Keay, R.W.J.,1964,Nigerian Trees Vol.2,Nigeria Federal Department of Forest Research, Ibadan Kennedy, J.D.,1936,Forest Flora of Southern Nigeria,Government Printer Lagos Pieters, A.,1977,Essences Forestieres du Zaire,R.U.G. Gent Belguim Sallenave, P.,1955,Proprietes Phyiques et Mecaniques des Bois Tropicaux de l'Union Francaise,C.T.F.T Takahashi, A.,1978,Compilation of Data on the Mechanical Properties of Foreign Woods (Part,III) Africa,Shimane University, Japan, Research Report on Foreign Wood No. 7 Taylor, C.J.,1960,Synecology and Silviculture in Ghana,University College of Ghana Thomas Nelson and Sons WCMC. 1992. Conservation Status Listing - Trees and Timbers of the World. World Conservation Monitoring Center-Plants Programme, Cambridge, CB3 ODL, United Kingdom.