|
| Commercial timbers |
Nomenclature etc. FABACEAE-CAESALPINIOIDEAE. I. bijuga (Colebr.) O. Kuntze (syn.: Macrolobium bijugum Colebr., Afzelia bijuga (Colebr.) A.Gray; I. palembanica Miq. (syn.: Afzelia palembanica Baker, A. bakeri Prain, A. bijuga Kurz, Intsia bakeri Prain). Trade and local names: merbau (MY); malacca teak, mirabow, Moluccan ironwood (GB); ipil, kayu besi (ID); kwila, bendora (PG); ipil, ipil laut, malaipil (PH); tat-takun (MM); krakas prak (KH); lumpho, lumpho thale (TH); hintzy (MG). Not protected under CITES regulations.
Tree. Geographic distribution: Myanmar (Burma), Thailand, Laos, Vietnam, Cambodia, Indomalesia, Pacific Islands, Australia, Madagascar & other islands.
General. Growth ring boundaries distinct (demarcated by marginal parenchyma bands). Heartwood basically brown, red; without streaks. Sapwood colour distinct from heartwood colour. Density (0.5–)0.69–0.96 g/cm³. As opposed to 'Afzelia' the yellowish brown extractives in 'merbau' are water soluble and can be washed out causing nasty stains.
Vessels. Wood diffuse porous. Vessels arranged in no specific pattern, in multiples, commonly in short (2–3 vessels) radial rows. Average tangential vessel diameter 120–200–280 µm. Average number of vessels/mm² 2–3(–5). Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 5–7 µm, pits vestured. Vessel-ray pits with distinct borders, similar to intervessel pits. Helical thickenings absent. Tyloses absent. Other deposits present (white or yellow and dark reddish brown).
Tracheids and fibres. Fibres of medium wall thickness to very thick-walled. Average fibre length 560–790 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). Bands fine. Axial parenchyma paratracheal. Paratracheal axial parenchyma aliform, or confluent. Aliform parenchyma of the lozenge type. Axial parenchyma as strands. Average number of cells per strand: 2(–4).
Rays. Rays 5–8 per tangential mm, multiseriate, (1–)2(–4) cells wide. Height of large rays up to 500 µm. Rays composed of a single cell type (homocellular); homocellular ray cells procumbent.
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 not observed.
Physical and chemical tests. Heartwood fluorescent (yellow). Water extract not fluorescent; colour of water extract colourless to brown, or yellow. Heartwood extractives leachable when in contact with water. Ethanol extract fluorescent (yellow). Colour of ethanol extract colourless to brown, or yellow. Froth test negative. Splinter burns to partial ash. Ash bright white.
Illustrations. • Macroscopic images. Intsia bijuga. transverse (ca. 10x). radial (natural size). • Transverse section. Intsia bijuga. • Tangential section. Intsia bijuga. • Radial section. Intsia bijuga.
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’.
