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Nomenclature etc. SAPOTACEAE. According to Malaysian Grading Rules the following species: Palaquium hexandrum, P. hispidum, P. impressinervium, P. maingayi, P. obovatum, P. regina-montium, P. semaram, P. sumatranum, P. walsurifolium, Palaquium spp. Trade and local names: chay (VN); pencil cedar, red planchonella (PG); pali (IN); nato (PH); kha-nunnok (TH); riam, jangka (MY-SWK); hangkang, balam teruing puteh, balam masin, kayu tanjung hutan, mayang, taban (MY, ID); moordooke (AU). Not protected under CITES regulations.
Tree. Geographic distribution: Thailand, Laos, Vietnam, Cambodia, Indomalesia, Pacific Islands.
General. Growth ring boundaries distinct or indistinct or absent. If at all distinct, demarcated by lesser number of parenchyma bands (darker zone). Heartwood basically brown, red. Sapwood colour distinct from heartwood colour. Density 0.4–0.65(–1.02) g/cm³. Density quite variable, timbers therefore attributed to different trade groups, i.e. 'nyatoh' (medium weight) and 'nyatoh batu' (heavy).
Vessels. Vessels present. Wood diffuse porous. Vessels arranged in mostly a diagonal and/or radial pattern or no specific pattern, in multiples, commonly in short (2–3 vessels) radial rows or in radial rows of 4 or more. Average tangential vessel diameter 60–150–270 µm. Average number of vessels/mm² 3–8–13(–40). Average vessel element length 440–900–1250 µm. Perforation plates simple or scalariform (very few), with 3–10 bars. Intervessel pits alternate, average diameter (vertical) 4–8 µm. Vessel-ray pits with distinct borders or with reduced borders or apparently simple, similar to intervessel pits or different from intervessel pits, rounded or angular or horizontal to vertical, of two distinct sizes or types in the same ray cell, located throughout the ray. Tyloses present, thinwalled. Other deposits present (reddish brown).
Tracheids and fibres. Vascular or vasicentric tracheids commonly present. Fibres very thin-walled, or of medium wall thickness, or very thick-walled (nyatoh batu). Average fibre length 1300–1760–2310 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres non-septate.
Axial parenchyma. Axial parenchyma banded. Bands marginal (or seemingly marginal) or not marginal (or seemingly marginal). Axial parenchyma bands forming a reticulate pattern with rays. Bands fine, (3–)6(–12) per radial mm. Axial parenchyma apotracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Axial parenchyma as strands. Average number of cells per strand: 4–12.
Rays. Rays 8–12 per tangential mm, multiseriate, 1–3 cells wide. Rays with multiseriate portions as wide as uniseriate portions absent. 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 2–4 marginal rows of upright or square cells or with more than 4 marginal rows of upright or square cells.
Storied structures. Storied structure absent.
Secretory structures. Intercellular canals absent.
Mineral inclusions. Crystals present, prismatic, located in axial parenchyma cells. Crystal-containing axial parenchyma cells chambered. Number of crystals per cell or chamber one. Silica present (nyatoh batu) or not observed, as grains; in rays cells.
Physical and chemical tests. Froth test positive.
Illustrations. • Macroscopic images. transverse (ca. 10x). radial (natural size). • Transverse section. Palaquium hexandrum. • Tangential section. Palaquium obovatum. • Radial section. Palaquium hexandrum. • Crystals. Palaquium sumatranum. prismatic crystals in chambered parenchyma cells (semi-polarized light).
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’.
