Commercial Timbers


H. G. Richter and M. J. Dallwitz

Pterocarpus indicus Willd. (Amboina, narra)

Nomenclature etc. FABACEAE-FABOIDEAE. Trade and local names: Amboine, santal rouge (FR); amboyna, red sandalwood, padauk (GB); angsana (BN, ID, MY); sonokembang (ID); New Guinea rosewood (PG); apalit, vitali (PH); sena, padouk, ansanah (MM); chan dêng (LA); pradu, sano (TH). Not protected under CITES regulations.

Description based on 13 specimens. Tree. Geographic distribution: Burma, Thailand, Laos, Vietnam, Cambodia, and Indomalesia.

General. Growth ring boundaries distinct and indistinct or absent. Nearly semi-ringporous in some specimens. Heartwood basically brown, with streaks. Sapwood colour distinct from heartwood colour. Density 0.55–0.9 g/cm³.

Vessels. Vessels present. Wood ring-porous and semi-ring-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows, radial rows of 4 or more, and in clusters. Vessel outline rounded. Two distinct vessel diameter classes absent. Average tangential vessel diameter 100–180–250 µm; diameter of vessel lumina: large and very large. Average number of vessels/mm² 2–4; vessels per square millimetre very few. Average vessel element length 200–300 µm. Average vessel element length short. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 8–12 µm, medium and large, vestured. Vessel-ray pits with distinct borders, similar to intervessel pits, of uniform size or type, of the same type in adjacent elements, located throughout the ray. Helical thickenings absent. Tyloses in vessels absent. Other deposits in heartwood vessels present, pinkish brown deposits.

Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres very thin-walled and of medium wall thickness. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent. Fibres non-septate.

Axial parenchyma. Axial parenchyma present, banded and not banded. Axial parenchyma bands marginal (or seemingly marginal) and not marginal (or seemingly marginal), bands much wider than rays, fine, up to three cells wide. Axial parenchyma apotracheal and paratracheal. Apotracheal axial parenchyma diffuse. Paratracheal axial parenchyma vasicentric, aliform, and confluent. Aliform parenchyma winged. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 2. Unlignified parenchyma absent. Apotracheal parenchyma with crystals.

Rays. Rays present, 6–14 per tangential mm, exclusively uniseriate and multiseriate (also if only few), 1(–2) cells wide, narrow (2–3 seriate). Rays with multiseriate portions as wide as uniseriate portions absent. Aggregate rays absent. Rays of one size. Height of large rays up to 500 µm. Rays composed of a single cell type (homocellular); homocellular ray cells procumbent. Sheath cells absent. Tile cells absent. Perforated ray cells absent. Disjunctive ray parenchyma end walls indistinct or absent.

Storied structures. Storied structure present, all rays storied, axial parenchyma storied, vessel elements storied, fibres storied. Arrangement of tiers regular (horizontal or straight).

Secretory structures. Oil and mucilage cells absent. Intercellular canals absent. Laticifers or tanniniferous tubes absent.

Cambial variants. Included phloem absent. Other cambial variants 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. Crystal containing cells of normal size. Cystoliths absent. Silica not observed.

Physical and chemical tests. Heartwood fluorescent. Water extract fluorescent; basically yellow or shade of yellow. Heartwood extractives leaching out when in contact with water. Ethanol extract fluorescent. Colour of ethanol extract red or shade of red. Chrome azurol-S test negative. Froth test positive (weakly positive). Splinter burns to partial ash. Ash white to grey.

Illustrations. • Transverse section 1. Pterocarpus indicus. Wood ringporous to semi-ringporous. • Transverse section 2. Pterocarpus indicus. Wood semi ringporous to diffuse porous. • Tangential section. Pterocarpus indicus. • Radial section. Pterocarpus indicus.

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: 25th June 2009.’.