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| Commercial timbers |
Nomenclature etc. FABACEAE-CAESALPINIOIDEAE. Trade and local names: ayan, anyaran (GB, NG), barré, guétalie, koa (CI), bonsamdua, duabai (GH), okpe (TG), bosong, eyen, sella (CM), muvenghi, eyen, ogueminya (GA); eyen, bien (GQ). Not protected under CITES regulations.
Tree. Geographic distribution: tropical Africa.
General. Heartwood basically yellow to brown (yellow when green, darkening to yellowish brown). Sapwood colour distinct from heartwood colour. Odour indistinct or absent. Density 0.6–0.68–0.8 g/cm³.
Vessels. Wood diffuse porous. Vessels in multiples, commonly in short (2–3 vessels) radial rows. Average tangential vessel diameter 120–180–255 µm. Average number of vessels/mm² 2–7(–14). Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 9–13 µm, pits vestured. Vessel-ray pits with distinct borders, similar to intervessel pits. Other deposits present (honey colored and very dark brown).
Tracheids and fibres. Fibres of medium wall thickness. Average fibre length 1000–1350–1750 µm. Fibre pits common in both radial and tangential walls, simple to minutely bordered. Fibres non-septate.
Axial parenchyma. Axial parenchyma not banded. Axial parenchyma apotracheal, or paratracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma aliform, or confluent. Aliform parenchyma of the lozenge type. Axial parenchyma as strands. Average number of cells per strand: 2–4.
Rays. Rays 4–10 per tangential mm, multiseriate, 2–5 cells wide. Height of large rays up to 500 µm. Rays composed of two or more cell types (heterocellular). Heterocellular rays with square and upright cells restricted to marginal rows, mostly mostly 1 marginal row of upright or square cells or mostly 2–4 marginal rows of upright or square cells.
Storied structures. Storied structure present, all rays storied, axial parenchyma storied, vessel elements storied, fibres not storied.
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, upright and/or square ray cells chambered or not chambered. Crystal-containing axial parenchyma cells chambered. Number of crystals per cell or chamber one. Druses and micro crystlas occur sporadically. Silica present, as grains or in aggregates; in rays cells and in axial parenchyma.
Illustrations. • Transverse section. • Tangential section. • Radial section. • Mineral inclusions. Distemonanthus benthamianus. prismatic crystals and silica occur in rays (left) as well as in axial parenchyma (right). • Crystals. Distemonanthus benthamianus. occasional presence of crystal sand (left under normal and polarized light), druses (centre), and different size prismatic crystals (right).
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’.
