Commercial Timbers


H. G. Richter and M. J. Dallwitz

Shorea spp., subg. Shorea (Balau, bangkirai)

Nomenclature etc. DIPTEROCARPACEAE. Shorea atrinervosa Sym., S. brunnescens, S. crassa Ashton, S. exelliptica Meijer, S. foxworthyi Sym., S. glauca King, S. havilandii Brandis, S. laevis Ridl. ( (coded separately) , S. leptoderma Meijer, S. maxwelliana King, S. materialis Ridl., S. seminis (de Vriese) v. Slooten, S. submontana Sym., S. sumatrana (v. Sl. ex Foxw.) Sym., S. superba Sym. Trade and local names: balau, selangan batu No. 1, - No. 2 (MY, DE), selangan batu tatuk, balau bukit, hitam, kumus hitam, laut, laut merah, sengkawang, damar laut (MY), balau bunga, bangkirai, semantok lungkik (ID), yakal (PH), teng (TH). Not protected under CITES regulations.

Tree. Geographic distribution: India, Pakistan, Sri Lanka, Burma, Thailand, Laos, Vietnam, Cambodia, and Indomalesia.

General. Heartwood basically brown to yellow to white or grey brown to green. Sapwood colour distinct from heartwood colour. Density 0.7–0.9–1.05 g/cm³.

Vessels. Wood diffuse-porous. Vessels in multiples, commonly short (2–3 vessels) radial rows. Average tangential vessel diameter 110–170–230 µm. Average number of vessels/mm² 2–10. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 5–8 µm, vestured. Vessel-ray pits with distinct borders and with reduced borders or apparently simple, similar to intervessel pits, rounded or angular and horizontal to vertical. Tyloses in vessels present, thinwalled.

Tracheids and fibres. Vascular or vasicentric tracheids commonly present. Fibres very thick-walled. Fibre pits mainly restricted to radial walls, simple to minutely bordered.

Axial parenchyma. Axial parenchyma banded and not banded. Axial parenchyma bands marginal (or seemingly marginal), fine, up to three cells wide. Axial parenchyma apotracheal and paratracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma vasicentric, aliform, confluent, and unilateral. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 4.

Rays. Rays 6–10 per tangential mm, multiseriate (also if only few), (1–)2–4 cells wide. 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 present, rays not storied, axial parenchyma storied.

Secretory structures. Intercellular canals present, axial type, in long tangential lines and in short tangential lines.

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, or enlarged (idioblasts). Silica not observed.

Physical and chemical tests. Water extract basically colourless to brown or shade of brown (brown). Heartwood extractives leaching out when in contact with water (brown).

Illustrations. • Macro images. Shorea sp., subg. Shorea. Transverse. Radial. • Transverse section. Shorea maxwelliana. • Tangential section. Shorea maxwelliana. • Radial section. Shorea maxwelliana.

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.’.