Commercial timbers

H. G. Richter and M. J. Dallwitz


Gluta spp. (Rengas)

Nomenclature etc. ANACARDIACEAE. Important species: Gluta curtisii, G. papuana, G. renghas, G. wallichii; Hölzer der Gattung Melanochyla werden häufig auch als Rengas gehandelt timbers of the genus Melanochyla are also traded as rengas. Trade and local names: rengas (trade); rengas kerbau jalang (MAL); rengas tembaga (RI); hekakoro (PNG); thayet-thitsi (BUR); kroeul (K); rakban (T).

Tree. Geographic distribution: Burma to Indomalesia, or Madagascar & other islands.

General. Growth ring boundaries distinct. Heartwood basically brown red, with streaks. Sapwood colour distinct from heartwood colour. Odour indistinct or absent. Basic specific gravity 0.57–0.8 g/cm³. Colour of heartwood variable: in some species uniformly greyish brown, in others deep reddish brown with black streaks.

Vessels. Wood diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows or radial rows of 4 or more. Vessel outline rounded. Average tangential vessel diameter 115–260 µm. Average number of vessels/mm² 2–6. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 9–12 µm, not vestured. Vessel-ray pits with reduced borders or apparently simple, different from intervessel pits, rounded or angular, unilaterally compound and coarse. Tyloses in vessels present, thinwalled or sclerotic.

Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres of medium wall thickness, or very thick-walled. Average fibre length 600–1200 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres non-septate.

Axial parenchyma. Axial parenchyma present, banded. Axial parenchyma bands marginal (or seemingly marginal), fine, up to three cells wide or coarse, more than three cells wide. Axial parenchyma paratracheal. Paratracheal axial parenchyma vasicentric. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 3–4(–8).

Rays. Rays present, 4–12(–20) per tangential mm, exclusively uniseriate. Rays composed of a single cell type. Homocellular ray cells procumbent. Only rays containing radial canals are multiseriate.

Storied structures. Storied structure absent.

Secretory structures. Oil and mucilage cells absent. Intercellular canals present, non-traumatic origin, radial type. Laticifers or tanniniferous tubes absent.

Cambial variants. Included phloem absent.

Mineral inclusions. Crystals not observed. Silica present, as grains, in rays cells.

Physical and chemical tests. Heartwood extractives leaching out when in contact with water.


Cite this publication as: H. G. Richter and M. J. Dallwitz (2000 onwards). 'Commercial timbers: descriptions, illustrations, identification, and information retrieval.' In English, French, German, and Spanish. Version: 4th May 2000. http://biodiversity.uno.edu/delta/.

Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993 onwards, 1995 onwards, 1998) should also be cited (see General references).

Index