Swintonia spp. (merpauh)
Nomenclature etc. ANACARDIACEAE. S. floribunda, S. schwenkii. Trade and local names: merpauh (trade); selan (MAL-SWK); kaluis, lomarau (RP); civit, taung-thayet (BUR); muom (K, VN). Status of protection under CITES regulations: not protected.
Tree. Geographic distribution: Burma to Indomalesia.
General. Growth ring boundaries distinct (marked by marginal parenchyma bands). Heartwood basically brown to red, without streaks. Sapwood colour distinct from heartwood colour (greyish brown and often darker than heartwood). Odour indistinct or absent. Basic specific gravity 0.64–0.88 g/cm³. Very high sapwood proportion.
Vessels. Vessels present. Wood diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows. Average tangential vessel diameter 180–300 µm. Average tangential diameter of vessel lumina large to very large. Average number of vessels/mm² 2–8(–10). Vessels per square millimetre very few, or few. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 10–16 µm, large, not vestured. Vessel-ray pits with reduced borders or apparently simple, rounded or angular or horizontal to vertical. Helical thickenings absent. Tyloses in vessels present, thinwalled. Other deposits in heartwood vessels not observed.
Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres of medium wall thickness. Average fibre length 700–1000–1400 µm. Average fibre length medium. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent. Fibres non-septate.
Axial parenchyma. Axial parenchyma present, banded. Axial parenchyma bands marginal (or seemingly marginal) or not marginal (or seemingly marginal) (additional bands between marginal ones, irregular and often discontinuous), fine, up to three cells wide and 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 3–4. Unlignified parenchyma absent.
Rays. Rays present, 5–7 per tangential mm, multiseriate, also if only few, 2(–3) cells wide, 2–3 cells wide. Rays with multiseriate portions as wide as uniseriate portions absent. Aggregate rays absent. Rays of one size. Height of large rays up to 500 µm. Rays composed of a single cell type to two or more cell types. Homocellular ray cells procumbent. Heterocellular rays square and upright cells restricted to marginal rows. Number of marginal rows of upright or square cells 1. Sheath cells absent. Tile cells absent. Perforated ray cells absent. Disjunctive ray parenchyma end walls indistinct or absent.
Storied structures. Storied structure absent.
Secretory structures. Oil and mucilage cells absent. Intercellular canals present, non-traumatic origin, radial type. Laticifers or tanniniferous tubes absent.
Cambial variants. Included phloem absent. Other cambial variants 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 and not chambered. Crystal-containing axial parenchyma cells chambered. Number of crystals per cell or chamber one. Crystal containing cells of normal size. Cystoliths absent. Silica present and not observed, as grains, in rays cells. In specimens from the northern part of generic distribution SiO2 regularly present, in specimens from Sumatra very rare or absent.
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).