Swietenia macrophylla King (Echtes Mahagoni, true mahogany, caoba)
Nomenclature etc. MELIACEAE. Syn.: S. candollei Pittier, S. krukovii Gleason, S. tessmannii Harms, S. belizensis Lundell. Trade and local names: Amerikanisches Mahagoni, Echtes Mahagoni, Honduras-, Tabasco-, Nicaragua-Mahagoni (D);, caoba (cAm), aguano (PA, PE, BR); orura (YV); zopilote (MEX); sapoton (SME); yulu (NIC), crura (BOL); acajou d'Amérique (F), American mahogani, baywood (GB), broadleaf mahagony (USA). Status of protection under CITES regulations: S.humilis and S. mahagoni in annex II; S. macrophylla in annex III (Costa Rica).
Tree. Geographic distribution: Mexico and Central America and tropical South America (except Amazon basin).
General. Growth ring boundaries distinct, growthring limits marked by marginal parenchyma bands. Heartwood basically brown (light brown) brown to red (darkening upon exposure, golden luster), without streaks. Sapwood colour distinct from heartwood colour. Basic specific gravity 0.4–0.5–0.65 g/cm³. Grain interlocked (ribbon figure) and/or irregular near branches or crotches (variously figured wood).
Vessels. Wood diffuse-porous. Vessels in multiples, commonly short (2–3 vessels) radial rows. Average tangential vessel diameter 90–160–255 µm. Average number of vessels/mm² 2–18. Average vessel element length 480–890 µm. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 2–4 µm. Vessel-ray pits with distinct borders, similar to intervessel pits. Tyloses in vessels absent. Other deposits in heartwood vessels present (mostly dark reddish brown, less frequently white).
Tracheids and fibres. Fibres of medium wall thickness. Average fibre length 700–1000–1750 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres exclusively septate, or septate and non-septate (non-septate fibres few). Septate fibres evenly distributed.
Axial parenchyma. Axial parenchyma present, banded. Axial parenchyma bands marginal (or seemingly marginal), fine, up to three cells wide or coarse, more than three cells wide. Axial parenchyma paratracheal. Paratracheal axial parenchyma scanty to vasicentric. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 4–8.
Rays. Rays 5–10 per tangential mm, multiseriate, also if only few, 1–2–4(–5) cells wide. Rays composed of a single cell type, or two or more cell types. Homocellular ray cells procumbent, or square or upright. Heterocellular rays square and upright cells restricted to marginal rows. Number of marginal rows of upright or square cells 1, or 2–4. Ray cells of different sizes, tangential section.
Storied structures. Storied structure present or absent, all rays storied, axial parenchyma storied, vessel elements storied. Arrangement of tiers regular (horizontal or straight), or irregular. Storied rays not in all specimens present.
Secretory structures. Oil and mucilage cells absent. Intercellular canals present or absent, traumatic origin, axial type, rarely in long tangential lines or in short tangential lines. Laticifers or tanniniferous tubes absent.
Mineral inclusions. Crystals present, prismatic, located in ray cells and axial parenchyma cells. Crystal-containing ray cells upright and/or square and procumbent (infrequent in procumbent ray cells). Number of crystals per cell or chamber one. Silica not observed.
Miscellaneous. • Wood surface. Swietenia macrophylla. radial plane. tangential plane. • Transverse section. Swietenia macrophylla. • Tangential section. Swietenia macrophylla. • Radial section. Swietenia macrophylla.
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).
