Commercial Timbers


H. G. Richter and M. J. Dallwitz

Beilschmiedia spp. Tropical Asia (Medang)

Nomenclature etc. LAURACEAE. 35 species from tropical Asia and the australo-pacific region. Trade and local names: medang (trade); huru (ID); bagaoring (PH); kyese (MM); chick dong (LA). Not protected under CITES regulations.

Description based on 35. Tree. Geographic distribution: India, Pakistan, Sri Lanka, Burma, Thailand, Laos, Vietnam, Cambodia, Indomalesia, Australia, and New Zealand.

General. Growth ring boundaries distinct. Growth ring limits demarcated by marginal parenchyma bands. Heartwood basically white or grey, with streaks or without streaks. Sapwood colour similar to heartwood colour. Odour indistinct or absent. Density 0.45–0.65 g/cm³. Wood of commercial potential.

Vessels. Vessels present. Wood 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 90–150–240 µm; diameter of vessel lumina: large. Average number of vessels/mm² 3–12; vessels per square millimetre very few and few. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) (5–)7–11(–14) µm, medium, not vestured. Small intervessel pits (5–7 µm) only in B. tawa. Vessel-ray pits with reduced borders or apparently simple, rounded or angular, of uniform size or type, of the same type in adjacent elements, located throughout the ray. Helical thickenings absent. Tyloses in vessels present, thinwalled. Other deposits in heartwood vessels not observed.

Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres very thin-walled and of medium wall thickness. Average fibre length 900–1200–1450 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered and distinctly bordered. Helical thickenings absent. Fibres non-septate.

Axial parenchyma. Axial parenchyma present, banded. Axial parenchyma bands marginal (or seemingly marginal), bands much wider than rays, fine, up to three cells wide and coarse, more than three cells wide. Axial parenchyma apotracheal and paratracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma vasicentric and aliform. Aliform parenchyma lozenge. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 2–4. Unlignified parenchyma absent.

Rays. Rays present, 4–8 per tangential mm, multiseriate (also if only few), (1–)2–4 cells wide, narrow (2–3 seriate) and of medium width (3–5 seriate). Rays with multiseriate portions as wide as uniseriate portions absent. Aggregate rays absent. Rays of two distinct sizes, or of one size. 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. Sheath cells absent. 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 present and absent, associated with axial parenchyma, ray parenchyma, and fibres. Oil and/or mucilage cells can be absent in some species or specimens. Intercellular canals absent. Laticifers or tanniniferous tubes absent.

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

Mineral inclusions. Crystals present or not observed, in other forms (usually very small: prismatic, tabletoid, spindle-shaped, splinters), located in ray cells and axial parenchyma cells. Crystal-containing ray cells upright and/or square and procumbent, upright and/or square ray cells not chambered. Crystals in procumbent ray cells not in radial alignment. Crystal-containing axial parenchyma cells not chambered. Number of crystals per cell or chamber more than one. Crystals in one cell or chamber of the same size, or of two distinct sizes. Crystal containing cells of normal size. Cystoliths absent. Crystals observed in: B. assamica (Syn.: B. praecox), B. erythrophloia, B. fordiana, B. gammieana, B. gemmiflora, B. glauca, B. intermedia, B. laevis, B. lucidula, B. maingayi, B. tawa, B. tsangii, B. undulata, B. wightii. Silica present and not observed, as grains and in aggregates, in rays cells and in axial parenchyma (rarely). Silica observed in: B. albiramea, B. bancroftii, B. bullata, B. castrisinensis, B. dictyoneura, B. elliptica, B. madang, B. malaccensis, B. micrantha, B. obtusifolia, B. oligandra, B. peninsularis.

Physical and chemical tests. Heartwood not fluorescent. Water extract fluorescent; basically colourless to brown or shade of brown. Heartwood extractives not leachable by water. Ethanol extract not fluorescent. Colour of ethanol extract colourless to brown or shade of brown. Chrome azurol-S test negative. Froth test negative. Splinter burns to partial ash. Ash white to grey.

Illustrations. • Transverse section. Beilschmiedia albiramea. B. assamica. • Tangential section. Beilschmiedia obtusifolia. • Ray size, oil cell. Rays of two distinct sizes (left); large idioblast (oil cell) associated with marginal parenchyma (right) in Beilschmiedia assamica. • Radial section. Beilschmiedia obtusifolia. • Crystals. Crystals of variable form and size in Beilschmiedia species. B. maingayi: fairly large and frequent. B. assamica: small and frequent. B. gammieana: small and infrequent. • Silica. Silica deposits of variable form and size in Beilschmiedia species. Left and bottom: Large aggregates in ray cells of B. micrantha. Small circular grains in B. bullata.

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.’.