Dipterocarpus spp. (Keruing)
Nomenclature etc. DIPTEROCARPACEAE. D. alatus - Syn. D. incanus Roxb., D. lemeslei Vesque; D. baudii Korth - Syn. D. duperreana Pierre, D. scortechinii King; D. grandiflorus (Blanco) Blanco - Syn. D. blancoi Blume, D. griffithii Miq., D. motleyanus Hook.f.; D. kerrii King - Syn. D. obconicus Foxw., D. perturbinatus Foxw., D. cuneatus Foxw.; D. costulatus v. Slooten; D. verrucosus Foxw. ex v. Slooten. Trade and local names: yang (F, T, VN), keruing (D), gurjun (AND, BUR, CL), dau (VN, F), white kanyin, kanyin-byu (BUR), chhoeuteal (K), nhang (LAO), keroewing (NL), yang hin, yang na (T), dzao long (VN). Status of protection under CITES regulations: not protected.
Tree. Geographic distribution: India, Pakistan, Sri Lanka, Burma, Thailand, Laos, Vietnam, Cambodia, and Indomalesia.
General. Growth ring boundaries distinct. Heartwood basically brown to red brown to yellow brown to green. Sapwood colour distinct from heartwood colour. Basic specific gravity 0.66–0.75–0.8 g/cm³.
Vessels. Wood diffuse-porous. Vessels exclusively solitary. Average tangential vessel diameter 110–210–285 µm. Average number of vessels/mm² 2–3–4. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 4–7 µm, vestured. Vessel-ray pits with reduced borders or apparently simple, rounded or angular, of uniform size or type and of two distinct sizes or types in the same ray cell, of the same type in adjacent elements and unilaterally compound and coarse. Tyloses in vessels present, thinwalled.
Tracheids and fibres. Vascular or vasicentric tracheids commonly present. Fibres of medium wall thickness. Average fibre length 1600–2100–2500 µm. Fibre pits common in both radial and tangential walls, distinctly bordered.
Axial parenchyma. Axial parenchyma not banded. Axial parenchyma apotracheal and paratracheal. Apotracheal axial parenchyma diffuse and diffuse-in-aggregates. Paratracheal axial parenchyma scanty and vasicentric. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 4–6.
Rays. Rays 5–9 per tangential mm, multiseriate, also if only few, (3–)4–6 cells wide. Rays composed of two or more cell types. Heterocellular rays square and upright cells restricted to marginal rows and procumbent, square and upright cells mixed throughout the ray. Number of marginal rows of upright or square cells 2–4 and more than 4. Sheath cells absent.
Secretory structures. Intercellular canals present, axial type, diffusely arranged.
Mineral inclusions. Crystals not observed. Silica present, as grains, in rays cells.
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).