Commercial Timbers


H. G. Richter and M. J. Dallwitz

Guibourtia arnoldiana (de Wild. & Th. Dur.) J. Léonard (Mutenye)

Nomenclature etc. FABACEAE-CAESALPINIOIDEAE. Syn.: Copaifera arnoldianai (de Wild. & Th. Dur.) Th. et H. Dur., Copaipa arnoldianai de Wild. & Th. Dur. Trade and local names: mutenye (DE, GB, BE, FR, CG, CD); benge; mutene (BE, CD); kouan, ogboneli (CM); benzi, libengé, nténé, tungi (CG); Phantasienamen: Jaspis- oder Paradies- Nussbaum (DE) : olivier tropical (FR); olive walnut (GB). Not protected under CITES regulations.

Tree. Geographic distribution: tropical Africa.

General. Growth ring boundaries indistinct or absent. Growth ring boundaries demarcated by marginal parenchyma bands and slight changes in vessel frequency. Heartwood basically yellow (grey-yellowish) green to brown (light brown to light olive), with streaks (with nearly black stripes). Sapwood colour distinct from heartwood colour. Density 0.78–0.88–0.96 g/cm³ (12–15% mc).

Vessels. Wood diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows. Average tangential vessel diameter 75–110–140 µm. Average number of vessels/mm² 9–15–27. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 5–8 µm, vestured. Vessel-ray pits with distinct borders, similar to intervessel pits. Helical thickenings absent. Other deposits in heartwood vessels present (dark brown).

Tracheids and fibres. Fibres of medium wall thickness to very thick-walled. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres non-septate. Fibre pits large and conspicuous.

Axial parenchyma. Axial parenchyma banded and not banded. Axial parenchyma bands marginal (or seemingly marginal), fine, up to three cells wide. Axial parenchyma apotracheal and paratracheal. Apotracheal axial parenchyma diffuse (mostly thick-walled, crystalliferous and located immediately adjacent to rays). Paratracheal axial parenchyma vasicentric, aliform, and confluent. Aliform parenchyma lozenge. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 2–4–6. Occasionally with thickened (sclerotic) cell walls.

Rays. Rays 4–9–17 per tangential mm, multiseriate (also if only few), (1–)3–5 cells wide. Rays with multiseriate portions as wide as uniseriate portions absent. Rays composed of a single cell type (homocellular); homocellular ray cells procumbent.

Storied structures. Storied structure absent.

Secretory structures. Intercellular canals absent. Laticifers or tanniniferous tubes absent.

Mineral inclusions. Crystals present, prismatic, located in axial parenchyma cells. Crystal-containing axial parenchyma cells chambered. Number of crystals per cell or chamber one. Silica not observed.

Physical and chemical tests. Heartwood not fluorescent. Water extract fluorescent (green); basically yellow or shade of yellow. Ethanol extract fluorescent (light blue). Colour of ethanol extract colourless to brown or shade of brown and yellow or shade of yellow (yellowish-brown). Froth test positive, or negative.

Illustrations. • Transverse section. Guibourtia arnoldiana. • Tangential section. Guibourtia arnoldiana. • Radial section. Guibourtia arnoldiana.

The interactive key allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, summaries of attributes within groups of taxa, and geographical distribution.

Cite this publication as: ‘Richter, H.G., and Dallwitz, M.J. 2000 onwards. Commercial timbers: descriptions, illustrations, identification, and information retrieval. In English, French, German, Portuguese, and Spanish. Version: 25th June 2009.’.