Commercial timbers

H. G. Richter and M. J. Dallwitz


Guarea spp. (Bossé)

Nomenclature etc. MELIACEAE. G. cedrata (A. Chev.) Pellegr. - Syn: G. alatipetiolata de Wild., Trichilia cedrata A. Chev.; G. laurentii de Wild. - Syn.: Trichilia reygaertii de Wild.; G. thompsonii Sprague & Hutch. Trade and local names: bossé (D, F, B, NL, ZRE); scented or white guarea (GB, WAN); bossé claire (F); bosasa, lisasa, dumbala (ZRE); divuiti (G); bossi, kwabohoro (GH); akuraten, obobonufua (WAN); timbi, ebangbembra, obobo (CAM); krassé, ibotou, anakué, krassain, m'bossa (CI); G. thompsonii: mutigbanaye (CI); black guarea (WAN); bossé foncé (F); bolon (CAM); guarea, diambi (ZRE).

Tree. Geographic distribution: tropical Africa.

General. Heartwood basically red to brown (G. cedrata salmon coloured darkening to orange brown) yellow to brown to red (G. thompsonii darkening to copper brown), without streaks. Sapwood colour distinct from heartwood colour. Odour distinct. Basic specific gravity 0.52–0.55–0.65 g/cm³ (G. thompsonii often heavier). Ribbon figure due to interlocked grain; occasionally exudation of coloured extractives.

Vessels. Wood diffuse-porous. Vessels in multiples, commonly short (2–3 vessels) radial rows. Average tangential vessel diameter 85–140–215 µm. Average number of vessels/mm² 7–10–15. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 2–4 µm. Vessel-ray pits with distinct borders, similar to intervessel pits. Tyloses in vessels absent. Other deposits in heartwood vessels present (dark brown).

Tracheids and fibres. Fibres of medium wall thickness. Average fibre length 800–1300–1550 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres exclusively septate. Septate fibres evenly distributed.

Axial parenchyma. Axial parenchyma banded and not banded. Axial parenchyma bands marginal (or seemingly marginal), fine, up to three cells wide or coarse, more than three cells wide. Axial parenchyma paratracheal. Paratracheal axial parenchyma aliform, confluent, and unilateral paratracheal (prdeominantly state 5). Axial parenchyma as strands. Average number of cells per axial parenchyma strand 6–8–10.

Rays. Rays 6–12 per tangential mm, multiseriate, also if only few, (1–)2–3 cells wide. Rays composed of a single cell type and two or more cell types. Homocellular ray cells procumbent. Heterocellular rays square and upright cells restricted to marginal rows. Number of marginal rows of upright or square cells 1.

Secretory structures. Oil and mucilage cells absent. Intercellular canals 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 present, as grains, in rays cells and in axial parenchyma.


Cite this publication as: H. G. Richter and M. J. Dallwitz (2000 onwards). 'Commercial timbers: descriptions, illustrations, identification, and information retrieval.' In English, French, German, and Spanish. Version: 4th May 2000. http://biodiversity.uno.edu/delta/.

Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993 onwards, 1995 onwards, 1998) should also be cited (see General references).

Index