Swartzia fistuloides Harms, S. madagascariensis (Taub.) Desv. (Pau rosa)
Nomenclature etc. CAESALPINIACEAE. Trade and local names: Pau rosa, pau ferro (MOC); oken (G); boto (CI); n'guessa (RCA); kissamba (RPC); nsakala (ZRE).
Tree. Geographic distribution: tropical Africa, or Madagascar & other islands.
General. Growth ring boundaries indistinct or absent. Heartwood basically brown to red purple, with streaks. Sapwood colour distinct from heartwood colour. Odour indistinct or absent. Basic specific gravity 0.9–1.05 g/cm³.
Vessels. Wood diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows. Average tangential vessel diameter 120–170 µm. Average tangential diameter of vessel lumina 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, medium, vestured. Vessel-ray pits with distinct borders, similar to intervessel pits. Helical thickenings absent. Tyloses in vessels absent. Other deposits in heartwood vessels present (amber to nearly black color de mbar hasta casi negro).
Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres of medium wall thickness, or very thick-walled. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres non-septate.
Axial parenchyma. Axial parenchyma banded. Axial parenchyma bands not marginal (or seemingly marginal), bands much wider than rays, fine, up to three cells wide or coarse, more than three cells wide. Axial parenchyma paratracheal. Paratracheal axial parenchyma aliform to unilateral paratracheal. Aliform parenchyma lozenge. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 2–4.
Rays. Rays 9–14 per tangential mm, multiseriate, also if only few, 2–3 cells wide, 2–3 cells wide. Height of large rays up to 500 µm. Rays composed of a single cell type. Homocellular ray cells procumbent.
Storied structures. Storied structure present, all rays storied, axial parenchyma storied, vessel elements storied, fibres storied. Arrangement of tiers regular (horizontal or straight), 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.
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).