Heritiera spp. (Mengkulang)
Nomenclature etc. STERCULIACEAE. H. javanica, H. simplicifolia, H. borneensis, H. elata. Trade and local names: Mengkulang (MAL); Palapi, Teraling, Tarrietia (RI); huynh (VN); dong chem, sempong, sonloc (K); lumbayau (RP); may nhom pa (LAO), kanzo (BUR).
Tree. Geographic distribution: Burma, Thailand, Laos, Vietnam, Cambodia, and Indomalesia.
General. Heartwood basically brown red (light to dark reddish brown). Sapwood colour distinct from heartwood colour. Basic specific gravity (0.55–)0.62–0.7(–0.8) g/cm³. Wood surface slightly oily due to rubber-like cell contents.
Vessels. Wood diffuse-porous. Vessels in multiples, commonly short (2–3 vessels) radial rows or radial rows of 4 or more. Some of the larger vessels typically appended with radial rows of many small and radially flattended vessels. Average tangential vessel diameter (100–)170–310 µm. Average number of vessels/mm² 1–4 (not counting vessel tails with many small vessels). Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 3–5 µm. Vessel-ray pits with distinct borders, similar to intervessel pits. Other deposits in heartwood vessels present (yellowish to reddish brown).
Tracheids and fibres. Fibres of medium wall thickness. Average fibre length 900–1600–2300 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered.
Axial parenchyma. Axial parenchyma banded. Axial parenchyma bands not marginal (or seemingly marginal), fine, up to three cells wide. Axial parenchyma apotracheal, or paratracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma scanty, or vasicentric. Axial parenchyma as strands. Average number of cells per axial parenchyma strand (2–)4.
Rays. Rays 3–10 per tangential mm, multiseriate, also if only few, (1–)3–7 cells wide. Rays of two distinct sizes. Height of large rays commonly over 1000 µm. Rays composed of two or more cell types. Heterocellular rays square and upright cells restricted to marginal rows. Number of marginal rows of upright or square cells 1, or 2–4. Sheath cells present.
Storied structures. Storied structure present, some rays storied, some not, axial parenchyma storied, vessel elements storied, fibres storied. All tissues storied except largest rays.
Secretory structures. Intercellular canals absent.
Mineral inclusions. Crystals present, prismatic, located in ray cells or axial parenchyma cells (rarely). Crystal-containing ray cells upright and/or square. Crystal-containing axial parenchyma cells not chambered. Number of crystals per cell or chamber one. Silica present, as grains, in rays cells or in axial parenchyma (very little in axial parenchyma). The occurrence of silica in asian representatives of the Heritiera/Tarrietia group is the only reliable feature separating the former from the african species (Tarrietia utilis and T. densiflora = Niangón.
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).