Commercial Timbers


H. G. Richter and M. J. Dallwitz

Anisoptera spp. (Mersawa)

Nomenclature etc. DIPTEROCARPACEAE. A. cochinchinensis Pierre - Syn.: A. cochinchinensis var. latifolia King; A. marginata Korth - Syn.: A. grandiflora Brandis; A. scaphula (Roxb.) Kurz - Syn.: A. glabra Kurz, Hopea scaphula Roxb., Vatica scaphula Dyer; A. thurifera (Blanco) Bl. - Syn.: A. vidaliana Brandis. Trade and local names: mersawa (DE, GB, MY, ID, NL), krabak (DE, TH), ven ven (VN), phdiec (KH), bac (LA), kaunghmu (MM), sanai, malai (ID), palosapis (PH), tenam, entenam (MY, ID-sum), garawa (ID-wIrian), bella rosa (US). Not protected under CITES regulations.

Tree. Geographic distribution: Thailand, Laos, Vietnam, Cambodia and Indomalesia.

General. Growth ring boundaries distinct. Heartwood basically brown to yellow. Sapwood colour distinct from heartwood colour. Density 0.6–0.65 g/cm³.

Vessels. Wood diffuse-porous. Vessels exclusively solitary. Average tangential vessel diameter 108–195–255 µm. Average number of vessels/mm² 6–9–13. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 5–7 µm, vestured. Vessel-ray pits with reduced borders or apparently simple, rounded or angular. Tyloses in vessels present, thinwalled.

Tracheids and fibres. Vascular or vasicentric tracheids commonly present. Fibres of medium wall thickness. Average fibre length 950–1385–2365 µm. Fibre pits common in both radial and tangential walls, distinctly bordered.

Axial parenchyma. Axial parenchyma apotracheal and paratracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma scanty, vasicentric, and aliform. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 2–4. Paratracheal parenchyma often incomplete (unilateral).

Rays. Rays 4–7 per tangential mm, multiseriate (also if only few), 2–8 cells wide. Rays of one size. Height of large rays commonly over 1000 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 2–4 marginal rows of upright or square cells. Sheath cells present. Rays weakly heterocellular.

Secretory structures. Intercellular canals present (resin canals), axial type, rarely in short tangential lines or diffusely arranged.

Mineral inclusions. Crystals not observed. Silica present, as grains, in rays cells. SiO2 quite frequent, primarily in marginal and sheath cells.

Illustrations. • Transverse section. Anisoptera polyandra. Anisoptera marginata. Note: Distribution of axial intercellular canals (IC) in Anisoptera spp. can be diffuse (left) and/or in tangential lines (right). IC . IC . IC . • Tangential section. Anisoptera scaphula. Note: Silica grains located primarily in larger, lateral ray cells. • Radial section. Anisoptera laevis.

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.’.