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Nomenclature etc. ANACARDIACEAE. Other species of Dracontomelon occasionally traded as 'dao' are: D. costatum (Borneo, Sumatra), D. lenticulatum (New Guinea). Trade and local names: Pacific walnut, New Guinea walnut (trade); dahu, sengkuang, basuong (ID); unkawang (MY-sar); mon, laup (PG); nga-bauk (MM); phrachao-ha-phra-ong (TH). Not protected under CITES regulations.
Tree. Geographic distribution: Myanmar (Burma), Thailand, Laos, Vietnam, Cambodia, Indomalesia.
General. Heartwood basically greyish brown; with streaks. Sapwood colour distinct from heartwood colour. Density 0.35–0.7 g/cm³.
Vessels. Wood diffuse porous. Vessels in multiples, commonly in short (2–3 vessels) radial rows. Average tangential vessel diameter 100–300 µm. Average number of vessels/mm² 1–3(–5). Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 10–14 µm. Vessel-ray pits with reduced borders or apparently simple, different from intervessel pits, rounded or angular or horizontal to vertical, of uniform size or type, of the same type in adjacent elements or unilaterally compound and coarse. Helical thickenings absent. Tyloses present, thinwalled.
Tracheids and fibres. Fibres very thin-walled, or of medium wall thickness. Average fibre length 1200–2000 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres exclusively septate, or septate and non-septate; evenly distributed.
Axial parenchyma. Axial parenchyma present. Axial parenchyma apotracheal, or paratracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma vasicentric, or aliform, or confluent. Aliform parenchyma of the lozenge type. Axial parenchyma as strands. Average number of cells per strand: 2–4.
Rays. Rays 5–7 per tangential mm, multiseriate, 2–3(–5) cells wide. Height of large rays up to 500 µm. Rays composed of two or more cell types (heterocellular). Heterocellular rays with square and upright cells restricted to marginal rows, mostly 1 marginal row of upright or square cells or mostly 2–4 marginal rows of upright or square cells. Sheath cells absent.
Storied structures. Storied structure absent.
Secretory structures. Oil and mucilage cells absent. Intercellular canals absent.
Mineral inclusions. Crystals present, prismatic, located in ray cells. Crystal-containing ray cells upright and/or square or procumbent. Number of crystals per cell or chamber one. Silica not observed.
Illustrations. • Transverse section. • Tangential section. • Radial section.
The interactive key allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, summaries of attributes within groups of taxa, and geographical distribution.
Cite this publication as: ‘Richter, H.G., and Dallwitz, M.J. 2000 onwards. Commercial timbers: descriptions, illustrations, identification, and information retrieval. In English, French, German, Portuguese, and Spanish. Version: 9th April 2019. delta-intkey.com’.
