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| Commercial timbers |
Nomenclature etc. MALVACEAE (STERCULIACEAE). Trade and local names: abachi (DE), obeche (NG, BE), wawa (GH, GB), ayous (FR, GH, CM), samba (CI, FR). Not protected under CITES regulations.
Tree. Geographic distribution: tropical Africa (tropical West Africa).
General. Growth ring boundaries distinct. Heartwood basically yellow to white or grey (rarely olive (discoloured heartwood)). Sapwood colour similar to heartwood colour. Density 0.25–0.35–0.55 g/cm³. With pronounced interlocked grain; discolorations by fungi frequent.
Vessels. Wood diffuse porous. Vessels in multiples, commonly in short (2–3 vessels) radial rows. Average tangential vessel diameter 200–250–280 µm. Average number of vessels/mm² 1–3–8. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 4–6 µm. Vessel-ray pits with distinct borders, similar to intervessel pits. Tyloses present, thinwalled.
Tracheids and fibres. Fibres very thin-walled and of medium wall thickness. Fibre pits mainly restricted to radial walls, simple to minutely bordered.
Axial parenchyma. Axial parenchyma paratracheal. Apotracheal axial parenchyma diffuse and diffuse-in-aggregates. Paratracheal axial parenchyma scanty, or vasicentric. Axial parenchyma fusiform and as strands. Average number of cells per strand: 2–4.
Rays. Rays 5–9 per tangential mm, multiseriate, 1–5 cells wide. Rays of two distinct sizes. Height of large rays commonly 500 to 1000 µm. Rays composed of two or more cell types (heterocellular). Heterocellular rays with procumbent, square and upright cells mixed throughout the ray. Sheath cells present. Tile cells present.
Storied structures. Storied structure present, some rays storied, some not, axial parenchyma storied, vessel elements storied, fibres storied. Number of ray tiers per axial millimetre 3–4. High rays usually extend over several storied strata.
Secretory structures. Intercellular canals absent.
Mineral inclusions. Crystals present, prismatic, located in ray cells and axial parenchyma cells. Crystal-containing ray cells upright and/or square and procumbent. Crystal-containing axial parenchyma cells not chambered. Number of crystals per cell or chamber one. Crystal containing cells of normal size. Silica not observed.
Illustrations. • Macroscopic images. transverse (ca. 10x). radial (natural size). • Transverse section. • Tangential section. • Radial section. tile cells »».
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’.
