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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: G. cedrata: scented or white guarea (GB, NG); bossé claire (FR); bosasa, lisasa, dumbala (CD); divuiti (GA); bossi, kwabohoro (GH); akuraten, obobonufua (NG); timbi, ebangbembra, obobo (CM); krassé, ibotou, anakué, krassain, m'bossa (CI); G. thompsonii: mutigbanaye (CI); black guarea (NG); bossé foncé (FR); bolon (CM); guarea, diambi (CD). Not protected under CITES regulations.
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). Sapwood colour distinct from heartwood colour. Odour distinct. Density 0.52–0.55–0.65 g/cm³ (G. thompsonii often heavier). Occasionally exudation of coloured extractives on the surface.
Vessels. Wood diffuse porous. Vessels in multiples, commonly in 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 absent. Other deposits 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; evenly distributed.
Axial parenchyma. Axial parenchyma banded and not banded. Bands marginal (or seemingly marginal) or not marginal (or seemingly marginal). Bands fine or coarse. Axial parenchyma apotracheal, or paratracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma aliform, confluent, and unilateral (predominantly unilateral). Aliform parenchyma of the winged type. Axial parenchyma as strands. Average number of cells per strand: 6–8–10.
Rays. Rays 6–12 per tangential mm, multiseriate, (1–)2–3 cells wide. Height of large rays up to 500 µm. Rays composed of a single cell type (homocellular) and two or more cell types (heterocellular); homocellular ray cells procumbent. Heterocellular rays with square and upright cells restricted to marginal rows, mostly 1 marginal row of upright or square cells.
Secretory structures. 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.
Physical and chemical tests. Heartwood not fluorescent. Water extract not fluorescent; colour of water extract colourless to brown. Ethanol extract not fluorescent. Colour of ethanol extract colourless to brown. Splinter burns to partial ash. Ash white to grey.
Illustrations. • Macroscopic images. Guarea cedrata. transverse (ca. 10x). tangential (natural size). • Transverse section: G. cedrata. Guarea cedrata. • Tangential section: G. cedrata. Guarea cedrata. • Radial section: G. cedrata. Guarea cedrata. • Silica. Guarea cedrata. • Transverse section: G. thompsonii. Guarea thompsonii. • Tangential section: G. thompsonii. Guarea thompsonii. • Radial section: G. thompsonii. Guarea thompsonii.
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: 9th April 2019. delta-intkey.com’.
