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| Commercial timbers |
Nomenclature etc. FABACEAE-CAESALPINIOIDEAE. Syn.: Abauria excelsa Becc., Koompassia parvifolia Prain. Trade and local names: mengaris (BN), menggeris, tapang (MY); sialang, manggis, kayu rajah (ID). Not protected under CITES regulations.
Description based on 6 specimens. Tree. Geographic distribution: Thailand, Laos, Vietnam, Cambodia, Indomalesia.
General. Heartwood basically brown and red. Sapwood colour distinct from heartwood colour. Density (0.57–)0.8–0.9(–1.12) g/cm³.
Vessels. Vessels present. Wood diffuse porous. Vessels in multiples, commonly in short (2–3 vessels) radial rows and in radial rows of 4 or more. Average tangential vessel diameter (90–)200(–290) µm. Average number of vessels/mm² 3–5. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 6–8 µm, pits vestured. Vessel-ray pits with distinct borders, similar to intervessel pits. Tyloses absent. Other deposits present, reddish brown organic deposits.
Tracheids and fibres. Fibres of medium wall thickness to very thick-walled. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent.
Axial parenchyma. Axial parenchyma banded and not banded. Bands not marginal (or seemingly marginal). Axial parenchyma bands much wider than rays. Bands coarse. Axial parenchyma apotracheal, or paratracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma aliform and confluent. Aliform parenchyma of the winged type. Axial parenchyma as strands. Average number of cells per strand: 6–10. Unlignified parenchyma absent.
Rays. Rays 5–7 per tangential mm, multiseriate, 2–3 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 1 marginal row of upright or square cells and mostly 2–4 marginal rows of upright or square cells.
Storied structures. Storied structure present or absent, all rays storied, axial parenchyma storied, vessel elements storied. Arrangement of tiers irregular. Number of ray tiers per axial millimetre 2. Storeying of rays more or less developed in different specimens.
Secretory structures. Intercellular canals absent.
Cambial variants. Included phloem present (streaks of very hard and brittle, stone-like tissue), diffuse.
Mineral inclusions. Crystals present, prismatic and druses, located in ray cells and axial parenchyma cells. Crystal-containing ray cells upright and/or square, upright and/or square ray cells chambered. Crystal-containing axial parenchyma cells chambered. Number of crystals per cell or chamber one. Silica not observed.
Physical and chemical tests. Heartwood not fluorescent. Water extract fluorescent (yellow); colour of water extract colourless to brown. Ethanol extract not fluorescent. Colour of ethanol extract colourless to brown. Froth test positive (weakly). Splinter burns to partial ash. Ash bright white.
Illustrations. • Transverse section. • Tangential section. • Radial section. • Crystals. druses in marginal ray cells; prismatic crystals in chambered axial parenchyma cells under normal (left) and polarized (right) 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’.
