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Nomenclature etc. FABACEAE-CAESALPINIOIDEAE. Syn. Swartzia fistuloides Harms; S. madagascariensis Desv. Trade and local names: pau rosa, pau ferro (MZ); oken (GH); boto (CI); n'guessa (CF); kissamba (CG); nsakala (CD). Not protected under CITES regulations.
Tree. Geographic distribution: tropical Africa, Madagascar & other islands.
General. Growth ring boundaries indistinct or absent. Heartwood basically brown to red, purple; with streaks. Sapwood colour distinct from heartwood colour. Density 0.9–1.05 g/cm³.
Vessels. Wood diffuse porous. Vessels arranged in no specific pattern, in multiples, commonly in short (2–3 vessels) radial rows. Average tangential vessel diameter 120–170 µm; diameter of vessels: large. Average number of vessels/mm² 10–20; vessels per square millimetre few. Average vessel element length 200–250 µm. Average vessel element length short. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 6.5–10 µm, average diameter (vertical) medium, pits vestured. Vessel-ray pits with distinct borders, similar to intervessel pits. Helical thickenings absent. Tyloses absent. Other deposits present (amber to nearly black).
Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres of medium wall thickness to very thick-walled. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres non-septate.
Axial parenchyma. Axial parenchyma banded. Bands not marginal (or seemingly marginal). Axial parenchyma bands much wider than rays. Bands fine or coarse. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma aliform to unilateral. Aliform parenchyma of the lozenge type. Axial parenchyma as strands. Average number of cells per strand: 2–4.
Rays. Rays 9–14 per tangential mm, multiseriate, 2–3 cells wide, narrow (2–3 seriate). Height of large rays up to 500 µm. Rays composed of a single cell type (homocellular); homocellular ray cells procumbent.
Storied structures. Storied structure present, all rays storied, axial parenchyma storied, vessel elements storied, fibres storied. Arrangement of tiers regular, or irregular. Number of ray tiers per axial millimetre 3–5.
Secretory structures. Oil and mucilage cells absent. Intercellular canals absent. Laticifers or tanniniferous tubes absent.
Cambial variants. Included phloem 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. Froth test negative.
Illustrations. • Transverse section. Bobgunnia madagascariensis. • Tangential section. Bobgunnia madagascariensis. • Radial section. Bobgunnia madagascariensis.
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’.
