Scientific Name
Acacia polyacantha
Trade Name
Acacia catechu
Family Name
Leguminosae
Synonyms
Acacia campylantha
Common Names
Acacia catechu, African catechu, African cutch, Chikwiku, Clutch tree, Confectioners gum, Ede, Egirigiryoi, Falcons claw acacia, Farichin haramata, Farichin shafu, Fatarlahi, Ghambwe, Gomanchein, Gorpila, Gourga, Hook thorn, Karkara, Karki, Karo, Kayar rakumi, Kibere, Kumbarshafo, Mubaimondora, Mugu, Mukoka, Mukongoliko, Ngobe, Odurakot, Shanab, Umpumpu, White thorn
Regions of Distribution
Africa, Oceania and S.E. Asia
Countries of Distribution [VIEW MAP]
India, South Africa, Sudan, Tanzania, Uganda, Zimbabwe
Common Uses
Agricultural implements, Charcoal, Flooring, Fuelwood, Heavy construction, Joinery, Light construction, Millwork, Mine timbers, Particleboard, Plywood, Poles, Posts, Railroad ties, Sporting Goods, Tool handles
Distribution Overview
Widespread in tropical Africa from the Gambia to Eritrea, Ethiopia, in the north, to the Transvaal in the south. A subspecies, polyacantha, occurs in India. A. polyacantha is suspected to have been introduced from the Indian sub-continent.in the olden days, and now completely naturalized.
In the Sudanian and Guinean savannas, restricted to well watered places in the South Sahel ecozone, around ponds and in the bottom of fossil valleys with a shallow water-table, but sensitive to water-logging. Not a gregarious nor very common species. A. polyacantha is a tree of the sub-humid to humid African tropics with a wide distribution from South Senegal to Ethiopia and East Africa.
Heartwood Color
| Brown | ||||||||||||
| Black | ||||||||||||
| Purple | ||||||||||||
| Red | ||||||||||||
| Pink | ||||||||||||
| Reddish brown | ||||||||||||
| Pale red to pink | ||||||||||||
| Dark brown | ||||||||||||
| Brown |
Sapwood Color
| White | ||||||||||||
| Yellow | ||||||||||||
| White to yellow |
Grain
| Even | ||||||||||||
| Straight |
| Straight |
Texture
| Coarse | ||||||||||||
| Coarse |
Natural Durability
| Durable | ||||||||||||
| Resistant to termites | ||||||||||||
| Non-resistant to powder post beetles | ||||||||||||
| Susceptible to insect attack | ||||||||||||
| Durable | ||||||||||||
| Susceptible to attack from powder post (Lyctid & Bostrychid) beetles | ||||||||||||
| Sapwood is susceptible to wood staining fungal attack | ||||||||||||
| Resistant to attack from termites (Isoptera) |
Kiln Schedules
| Dry at a slow speed |
Ease of Drying
| Slowly |
Kiln Drying Rate
| Naturally dries slowly |
Tree Size
| Tree height is 10-20 m | ||||||||||||
| Bole length is 0-10 m | ||||||||||||
| Tree height is 20-30 m |
Cutting Resistance
| Easy to saw | ||||||||||||
| Fairly Difficult to Very Difficult to saw | ||||||||||||
| Cutting Resistance with dry wood is easy | ||||||||||||
| Cutting Resistance with dry wood is difficult |
Gluing
| Fairly Easy to Very Easy | ||||||||||||
| Easy to glue |
Planing
| Fairly Difficult to Very Difficult | ||||||||||||
| Fairly Easy to Very Easy | ||||||||||||
| Difficult to plane | ||||||||||||
| Easy to plane |
Response to Hand Tools
| Easy to Work | ||||||||||||
| Easy to machine |
Polishing
| Fair to Good Results | ||||||||||||
| Satisfactory results |
Strength Properties
| Density (dry weight) = 46-52 lbs/cu. ft. | ||||||||||||
| Shrinkage, Tangential = fairly large | ||||||||||||
| Shrinkage, Radial = moderate | ||||||||||||
| Max. crushing strength = high | ||||||||||||
| Bending strength (MOR) = high |
Numerical Data
| Item | Green | Dry | English |
| Bending Strength | 13576 | 20956 | psi |
| Density | 47 | lbs/ft3 | |
| Maximum Crushing Strength | 6899 | 9945 | psi |
| Weight | 46 | 38 | lbs/ft3 |
| Radial Shrinkage | 4 | % | |
| Tangential Shrinkage | 9 | % | |
| Item | Green | Dry | Metric |
| Bending Strength | 954 | 1473 | kg/cm2 |
| Density | 753 | kg/m3 | |
| Maximum Crushing Strength | 485 | 699 | kg/cm2 |
| Weight | 737 | 608 | kg/m3 |
| Radial Shrinkage | 4 | % |
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
Brenan, J.P.M., Greenway, P.J.,1949,Check-lists of the Forest Trees and Shrubs of the British Empire,Imperial Forestry Institute, Oxford No.5 Tanganyika Territories Part 2
Eggeling, W.J.,1940,Indigenous Trees of Uganda,Govt. Printer Entebbe Uganda
Fanshawe, D.B.,1962,Fifty Common Trees of Northern Rhodesia,Natural Resources Board and Forestry Department, Ndola
Hughes, J.F.,1957,A Summary of Information Available on the Utilisation of Brachystegia,spiciformis,Tanzania Forest Dept. Util. Sec. Moshi – Utilisation Series,No.1
Irvine, F.R.,1961,Woody Plants of Ghana,O.U.P. London
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
Pardy, A.A.,1951,Notes on Indigenous Trees and Shrubs of S. Rhodesia – Acacia campylacantha,Ministry of Agriculture and Lands S. Rhodesia Bulletin,No.1606
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
Unwin, A.H.,1920,West African Forests and Forestry,T. Fisher Unwin Ltd. London
White, F.,1962,Forest Flora of Northern Rhodesia,O.U.P. London