Commercial Timbers


H. G. Richter and M. J. Dallwitz

Terminalia spp. Asia I (Indian laurel)

Nomenclature etc. COMBRETACEAE. Incl. T. arjuna Bedd., T. bellirica (Gaertn.) Roxb., T. bialata Steud., T. calamansanai (Blanco) Rolfe, T. chebula Retz., T. citrina (Gaertn.) Roxb. ex Fleming, T. crenulata Wight & Arn., T. elliptica Willd. (syn. T. alata B. Heyne ex Roth, T. tomentosa (Roxb. ex DC.) Wight & Arn.), T. pyrifolia (Presl.) Kurz. Trade and local names: T. elliptica: taukkyan (BUR); asna, sain (IND). T. arjuna: arjun, kumbuk (IND). T. bellirica: bahera (IND); thinsein (BUR); samaw pipék (T). T. bialata: white chuglam (IND). T. chebula: harra, white chuglam (IND); samo-thai (T); haritaka (PK); klampit (RI); panga (BUR); chieu-lieu (VN). T. citrina: binggas (RP); samo-dingu (T); blabah, mertaki (RI); harra (IND); jaha, jelawai, talisai, telinsi (MAL). Not protected under CITES regulations.

Description based on 12. Tree. Geographic distribution: India, Pakistan, Sri Lanka, Burma, Thailand, Laos, Vietnam, Cambodia, and Indomalesia.

General. Growth ring boundaries distinct and indistinct or absent. Growth ring limits, when microscopically distinct, demarcated by zones of thick-walled, radially flattened fibres (latewood).. Heartwood basically brown, with streaks and without streaks. Sapwood colour distinct from heartwood colour. Odour indistinct or absent. Density 0.7–1 g/cm³. Wood of commercial potential.

Vessels. Vessels present. Wood semi-ring-porous and diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows. Vessel outline rounded. Two distinct vessel diameter classes absent. Average tangential vessel diameter 150–300 µm; diameter of vessel lumina: large to very large. Average number of vessels/mm² 5–20; vessels per square millimetre few. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 6–10 µm, medium, 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 present or absent, thinwalled. Other deposits in heartwood vessels present and not observed, Colour of organic deposits either yellow, brown or reddish brown in different species..

Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres very thin-walled to of medium wall thickness. Average fibre length 1200–1400 µm. Average fibre length medium. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent. Fibres exclusively septate (T. elliptica, T. calamansanai), or non-septate. Septate fibres evenly distributed. No septa observed in T. alata, T. calamansanai, T. microcarpa.

Axial parenchyma. Axial parenchyma present, banded and not banded (banded parenchyma observed in some specimens of T. arjuna, T. bellirica). Axial parenchyma bands not marginal (or seemingly marginal), fine, up to three cells wide and coarse, more than three cells wide (more than 3 cells wide in some specimens of T. bellirica). Axial parenchyma paratracheal. Paratracheal axial parenchyma vasicentric, aliform, and confluent. Aliform parenchyma winged. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 4–7. Unlignified parenchyma absent.

Rays. Rays present, 9–15 per tangential mm, exclusively uniseriate (with very few 2-seriates). Aggregate rays absent. Rays of one size. Height of large rays up to 500 µm. Rays composed of a single cell type (homocellular) and two or more cell types (heterocellular); homocellular ray cells procumbent. Heterocellular rays with square and upright cells restricted to marginal rows, mostly 1 marginal row of upright or square cells. Tile cells absent. Perforated ray cells absent. Disjunctive ray parenchyma end walls indistinct or absent.

Storied structures. Storied structure absent.

Secretory structures. Oil and mucilage cells absent. Intercellular canals present or absent, traumatic origin (occasionally), axial type, in short tangential lines. Laticifers or tanniniferous tubes absent.

Cambial variants. Included phloem absent. Other cambial variants absent.

Mineral inclusions. Crystals present, prismatic and styloids or elongate, located in ray cells and axial parenchyma cells (in rays: T. chebula, T. citrina; in axial parenchyma: T. arjuna, T. bellirica, T. elliptica, T. pyrifolia; in both rays and axial parenchyma: T. crenulata, T. paniculata). Crystal-containing ray cells procumbent, upright and/or square ray cells not chambered. Crystals in procumbent ray cells in radial alignment, or not in radial alignment. Crystal-containing axial parenchyma cells chambered and not 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 not fluorescent. Water extract not fluorescent; basically yellow or shade of yellow. Heartwood extractives not leachable by water. Ethanol extract fluorescent. Colour of ethanol extract yellow or shade of yellow. Chrome azurol-S test negative. Froth test negative. Splinter burns to partial ash. Ash white to grey.

Illustrations. • Transverse section: T. chebula. Terminalia chebula. • Transverse section: T. elliptica. Terminalia elliptica (syn. T. tomentosa). • Tangential section. Terminalia elliptica (syn. T. tomentosa). • Radial section. Terminalia chebula. • Crystals in rays and axial parenchyma. Terminalia citrina. Styloid crystals in wood of Terminalia ("Indian laurel" group) in rays (here in radial alignment) (left) and in axial parenchyma (right). Terminalia pyrifolia.

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.’.