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Newtonia buchananii (Baker f.) G.C.C.Gilbert & Boutique

Fl. Congo Belge 3: 213 (1952).
Mimosaceae (Leguminosae - Mimosoideae)
Piptadenia buchananii Baker f. (1894).
Vernacular names
East African newtonia, forest newtonia (En). Mnyassa (Sw).
Origin and geographic distribution
Newtonia buchananii occurs from Nigeria east to Kenya, and south to Angola, Zambia, Zimbabwe and Mozambique.
The wood (trade names: newtonia, mufomoti, mafamuti) is used for tool handles, implements, carpentry, joinery, cabinet work, doors, door frames, bridges, boat building, vehicle bodies and fencing. It is suitable for light construction, flooring, interior trim, boxes, crates, veneer and plywood. It is used traditionally to make dugout canoes. It is also used as firewood and for charcoal production.
The leaves are used as fodder for livestock and as mulch, and the pods also serve as forage. Newtonia buchananii is planted as an ornamental tree and shade tree in coffee, tea and cocoa plantations; the crown gives a rather light shade. It can also be planted for stabilizing river banks.
In DR Congo an air-dried bark decoction is applied as powder to abscesses. The flowers are a good source of nectar and pollen for bees. In Mozambique the bark is used as an aphrodisiac.
Production and international trade
There are no statistics on production and international trade of Newtonia buchananii timber, but locally it has some importance, for instance in the East Usambara Mountains in Tanzania, where it was amongst the 5 most important timber species in the mid 1980s, although its importance seemed to have slightly declined by 2001. The average price of a plank of about 3.7 m × 0.3 m was US$ 4 in Tanzania in 2001.
The heartwood is pale brown, darkening to golden brown upon exposure, distinctly demarcated from the up to 5(–15) cm thick, greyish white sapwood. The grain is interlocked, texture moderately coarse to coarse. The wood has some stripe or ribbon figure and is lustrous.
The wood is medium-weight. At 12% moisture content, the density is (415–) 560–670(–740) kg/m³. The wood air dries and kiln dries satisfactorily, with little distortion but with some risk of checking. Boards 2.5 cm thick air dry in 6 weeks and boards 5 cm thick in 4–5 months. The rates of shrinkage are moderate, from green to oven dry 3.0–3.7% radial and 5.0–6.3% tangential. After drying, the wood is moderately stable in service.
The wood is fairly soft to moderately hard. At 12% moisture content, the modulus of rupture is 88–97 N/mm², modulus of elasticity 7100–10,600 N/mm², compression parallel to grain 39–50 N/mm², shear 11–14 N/mm², cleavage 11 N/mm radial and 17 N/mm tangential, and Janka side hardness 4630 N.
The wood is easy to saw, but with some tendency to split due to growth stresses. It works fairly easily by hand and machine tools, but mortising and boring are somewhat difficult. A cutting angle of 10° and sharp edges are recommended for planing of quarter-sawn stock, but for flat-sawn pieces an angle of 30° is sufficient. The use of a filler is needed to obtain a good finish. The wood holds screws and nails well, but there is a tendency to splitting; pre-boring is recommended. It glues more or less satisfactorily and peels well.
The heartwood is not durable to moderately durable. It showed moderate resistance to termite attacks, but is susceptible to powder-post beetle, pinhole borer and marine borer attacks. However, it is reportedly durable in fresh water, and is for that reason much used for canoes in Lake Victoria. The heartwood does not absorb preservatives, but the sapwood is only moderately resistant.
Deciduous, medium-sized to fairly large tree up to 40 m tall; bole often straight and cylindrical, branchless for up to 18(–25) m but often much less, up to 100(–185) cm in diameter, at base sometimes with buttresses up to 3.5 m high; bark surface smooth to slightly fissured, pale grey to greyish brown, inner bark pinkish red; crown spreading, flat; young twigs densely short-hairy. Leaves alternate, bipinnately compound with (7–)12–23 pairs of usually opposite pinnae; stipules absent or indistinct; petiole 0.5–1.5 cm long, rachis up to 25 cm long, with a stalked gland between each pair of pinnae; leaflets opposite, (24–)38–67 pairs per pinna, sessile, linear, 2–6(–9) mm × 0.5–2 mm, asymmetrical at base, acute at apex, slightly hairy at margin. Inflorescence an axillary or terminal spike-like false raceme up to 20 cm long, often many together at ends of twigs, hairy, densely flowered. Flowers bisexual, regular, 5-merous; pedicel up to 0.5 mm long; calyx with c. 1 mm long tube, slightly toothed, hairy outside; petals free, linear-oblong, 2–3 mm long, creamy to yellowish, hairy outside; stamens 10, free, c. 4 mm long, anthers with caducous gland at apex; ovary superior, ellipsoid, c. 1 mm long, with long stipe, hairy, style slender, curved. Fruit a flattened linear pod 10–32 cm × 1.5–2.5 cm, at base with stipe up to 2 cm long, brown, slightly transversely veined, dehiscent at one side, up to 7-seeded. Seeds oblong, flat, 4–7.5 cm long including the papery wing surrounding the seed, reddish brown, attached near one end.
Other botanical information
Newtonia comprises about 15 species and is restricted to Africa. It seems related to Fillaeopsis from central Africa and Lemurodendron from Madagascar. Newtonia buchananii may be confused with Piptadeniastrum africanum (Hook.f.) Brenan, which differs in the absence of glands on the leaves, its glabrous ovary and its seeds being attached at the middle.
Wood-anatomical description (IAWA hardwood codes):
Growth rings: (1: growth ring boundaries distinct); (2: growth ring boundaries indistinct or absent). Vessels: 5: wood diffuse-porous; 13: simple perforation plates; 22: intervessel pits alternate; (23: shape of alternate pits polygonal); 24: intervessel pits minute ( 4 μm); 29: vestured pits; 30: vessel-ray pits with distinct borders; similar to intervessel pits in size and shape throughout the ray cell; 42: mean tangential diameter of vessel lumina 100–200 μm; 43: mean tangential diameter of vessel lumina 200 μm; 46: 5 vessels per square millimetre; 47: 5–20 vessels per square millimetre; 58: gums and other deposits in heartwood vessels. Tracheids and fibres: 61: fibres with simple to minutely bordered pits; 65: septate fibres present; 68: fibres very thin-walled; 69: fibres thin- to thick-walled. Axial parenchyma: (78: axial parenchyma scanty paratracheal); 79: axial parenchyma vasicentric; (80: axial parenchyma aliform); (81: axial parenchyma lozenge-aliform); (83: axial parenchyma confluent); 91: two cells per parenchyma strand; 92: four (3–4) cells per parenchyma strand. Rays: 97: ray width 1–3 cells; 104: all ray cells procumbent; 115: 4–12 rays per mm. Mineral inclusions: (136: prismatic crystals present); (142: prismatic crystals in chambered axial parenchyma cells); (143: prismatic crystals in fibres).
(E. Ebanyenle, A.A. Oteng-Amoako & P. Baas)
Growth and development
In general, seedlings grow slowly and have low survival rates. This means that special care is needed in the early years. However, once established, usually after 1–3 years, the young trees grow fairly fast. Locally trees may be found flowering throughout the year. The winged seeds are mainly dispersed by wind, but distribution by water and birds is also possible. It has been reported that the tree is relatively short lived.
In Nigeria and Cameroon Newtonia buchananii is restricted to forest in highland areas at 1100–1800 m altitude. In East and southern Africa it occurs in evergreen rainforest, often along watercourses and lakes, at 600–2200 m altitude. It occurs in regions with 1100–3000 mm annual rainfall. Locally Newtonia buchananii can co-dominate the canopy layer of the forest, e.g. in Kibale National Park in Uganda, together with Parinari excelsa Sabine, Chrysophyllum gorungosanum Engl., Pouteria altissima (A.Chev.) Baehni and Olea capensis L.
Propagation and planting
One kg contains about 5300 seeds. Pods should preferably be collected from the tree when they turn brown and subsequently dried in the sun; then the seeds can be shaken out. The seeds do not show dormancy and germinate in 3–4 weeks, with usually up to 70% germination and sometimes even 90%. The seeds lose their viability quickly, and cannot be stored for more than a few weeks at room temperature. They are susceptible to insect attacks, and it is recommended to add ash for storage. Direct sowing has been tried in Tanzania, but survival of seedlings was low, up to only 26% after 10 years; a critical period for seedling survival was reached 1–3 years after sowing. Root suckers can also be used for propagation, and wildlings are occasionally collected for planting.
In regeneration studies in natural forest in Uganda, it was recorded that regeneration was poor under the parent trees and increased away from them. Regeneration of Newtonia buchananii seems to be stimulated by the presence of small gaps in the forest.
In some regions Newtonia buchananii occurs in high densities, as in some forests in Kenya, Uganda and Tanzania.
The boles have a tendency to split during felling operations.
Handling after harvest
Freshly harvested logs are liable to insect attacks and should be removed from the forest soon after felling to avoid damage to the wood.
Genetic resources
Newtonia buchananii is fairly widespread and locally common. Therefore, it does not seem to be threatened at present. However, in several regions, e.g. in the East Usambara Mountains in Tanzania, it has been subject to serious over-exploitation, whereas natural regeneration is often poor.
There are certainly prospects on the timber market for Newtonia buchananii. This may offer possibilities for increased commercialization of the species, but research on growth rates and propagation is needed, as well as development of suitable forest management methods to guarantee sustainable production in the future. It could be included more extensively in agroforestry systems.
Major references
• Bolza, E. & Keating, W.G., 1972. African timbers: the properties, uses and characteristics of 700 species. Division of Building Research, CSIRO, Melbourne, Australia. 710 pp.
• Brenan, J.P.M., 1970. Leguminosae (Mimosoideae). In: Brenan, J.P.M. (Editor). Flora Zambesiaca. Volume 3, part 1. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. 153 pp.
• Bryce, J.M., 1967. The commercial timbers of Tanzania. Tanzania Forest Division, Utilisation Section, Moshi, Tanzania. 139 pp.
• Burkill, H.M., 1995. The useful plants of West Tropical Africa. 2nd Edition. Volume 3, Families J–L. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 857 pp.
• CAB International, 2005. Forestry Compendium. Newtonia buchananii. [Internet] fc/datasheet.asp?CCODE=NEWTBU. Accessed February 2008.
• Katende, A.B., Birnie, A. & Tengnäs, B., 1995. Useful trees and shrubs for Uganda: identification, propagation and management for agricultural and pastoral communities. Technical Handbook 10. Regional Soil Conservation Unit, Nairobi, Kenya. 710 pp.
• Maundu, P. & Tengnäs, B. (Editors), 2005. Useful trees and shrubs for Kenya. World Agroforestry Centre - East and Central Africa Regional Programme (ICRAF-ECA), Technical Handbook 35, Nairobi, Kenya. 484 pp.
• Mbuya, L.P., Msanga, H.P., Ruffo, C.K., Birnie, A. & Tengnäs, B., 1994. Useful trees and shrubs for Tanzania: identification, propagation and management for agricultural and pastoral communities. Technical Handbook 6. Regional Soil Conservation Unit/SIDA, Nairobi, Kenya. 542 pp.
• Takahashi, A., 1978. Compilation of data on the mechanical properties of foreign woods (part 3) Africa. Shimane University, Matsue, Japan, 248 pp.
• World Agroforestry Centre, undated. Agroforestree Database. [Internet] World Agroforestry Centre (ICRAF), Nairobi, Kenya. Sites/TreeDBS/ aft.asp. Accessed April 2008.
Other references
• Beentje, H.J., 1994. Kenya trees, shrubs and lianas. National Museums of Kenya, Nairobi, Kenya. 722 pp.
• Brenan, J.P.M., 1959. Leguminosae subfamily Mimosoideae. In: Hubbard, C.E. & Milne-Redhead, E. (Editors). Flora of Tropical East Africa. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. 173 pp.
• Chifundera, K., 2001. Contribution to the inventory of medicinal plants from the Bushi area, South Kivu Province, Democratic Republic of Congo. Fitoterapia 72: 351–368.
• Coates Palgrave, K., 1983. Trees of southern Africa. 2nd Edition. Struik Publishers, Cape Town, South Africa. 959 pp.
• Gilbert, G. & Boutique, R., 1952. Mimosaceae. In: Robyns, W., Staner, P., Demaret, F., Germain, R., Gilbert, G., Hauman, L., Homès, M., Jurion, F., Lebrun, J., Vanden Abeele, M. & Boutique, R. (Editors). Flore du Congo belge et du Ruanda-Urundi. Spermatophytes. Volume 3. Institut National pour l’Étude Agronomique du Congo belge, Brussels, Belgium. pp. 137–233.
• InsideWood, undated. [Internet] Accessed May 2007.
• Keay, R.W.J., 1989. Trees of Nigeria. A revised version of Nigerian trees (1960, 1964) by R.W.J. Keay, C.F.A. Onochie and D.P. Stanfield. Clarendon Press, Oxford, United Kingdom. 476 pp.
• Lewis, G., Schrire, B., MacKinder, B. & Lock, M., 2005. Legumes of the world. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 577 pp.
• Mugasha, A.G., 1978. Direct sowing of Beilschmiedia kweo (Mildbr.) Robyns & Wilczek, Cephalosphaera usambarensis Warb. and Newtonia buchananii (Baker) Gilbert & Boutique at Amani and Kwamkoro, Tanzania. Tanzania Silviculture Technical Note 40. 11 pp.
• Parant, B., Chichignoud, M. & Curie, P., undated. Présentation graphique des caractères technologiques des principaux bois tropicaux. Tome 8. Bois du Burundi. CTFT, Nogent-sur-Marne, France. 82 pp.
• Roe, D., Mulliken, T, Milledge, S., Mremi, J., Mosha, S. & Grieg-Gran, M., 2002. Making a killing or making a living?: wildlife trade, trade controls and rural livelihoods. Biodiversity and Livelihoods Issues 6. TRAFFIC, Cambridge & IIED, London, United Kingdom. 114 pp.
• Tanzania Forest Division, 1962. Timbers of Tanganyika: Newtonia buchananii (newtonia, mkufi, mnyassa). Tanzania Forest Division, Utilisation Section, Moshi, Tanzania. 7 pp.
• Troupin, G., 1982. Flore des plantes ligneuses du Rwanda. Publication No 21. Institut National de Recherche Scientifique, Butare, Rwanda. 747 pp.
• Villiers, J.-F., 1990. Contribution à l’étude du genre Newtonia Baillon (Leguminosae - Mimosoideae) en Afrique. Bulletin du Jardin botanique national de Belgique 60: 119–138.
• Vivien, J. & Faure, J.J., 1985. Arbres des forêts denses d’Afrique Centrale. Agence de Coopération Culturelle et Technique, Paris, France. 565 pp.
• Williamson, J., 1955. Useful plants of Nyasaland. The Government Printer, Zomba, Nyasaland. 168 pp.
• Zambia Forest Department, 1979. Timbers of Zambia: Newtonia buchananii, Olea capensis. Zambia Forest Department, Division of Forest Products Research, Kitwe, Zambia. 4 pp.
Sources of illustration
• Brenan, J.P.M., 1959. Leguminosae subfamily Mimosoideae. In: Hubbard, C.E. & Milne-Redhead, E. (Editors). Flora of Tropical East Africa. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. 173 pp.
F.S. Mairura
Kenya Tropical Soil Biology and Fertility Institute of CIAT, P.O. Box 30677, Nairobi, Kenya

D. Louppe
CIRAD, Département Environnements et Sociétés, Cirad es-dir, Campus international de Baillarguet, TA C-DIR / B (Bât. C, Bur. 113), 34398 Montpellier Cedex 5, France
A.A. Oteng-Amoako
Forestry Research Institute of Ghana (FORIG), University P.O. Box 63, KNUST, Kumasi, Ghana
M. Brink
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
General editors
R.H.M.J. Lemmens
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
L.P.A. Oyen
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
J.R. Cobbinah
Forestry Research Institute of Ghana (FORIG), University P.O. Box 63, KNUST, Kumasi, Ghana
Photo editor
G.H. Schmelzer
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article:
Mairura, F.S., 2008. Newtonia buchananii (Baker f.) G.C.C.Gilbert & Boutique. In: Louppe, D., Oteng-Amoako, A.A. & Brink, M. (Editors). Prota 7(1): Timbers/Bois d’œuvre 1. [CD-Rom]. PROTA, Wageningen, Netherlands.
Distribution Map wild

1, flowering twig; 2, flower; 3, fruit; 4, seed.
Redrawn and adapted by Iskak Syamsudin

tree habit

base of bole
obtained from

Newtonia buchananii 161.tif

obtained from
Carlton McLendon, Inc.

wood in transverse section

wood in tangential section

wood in radial section