Nomenclature etc. EUPHORBIACEAE. Trade and local names: hevea, Hevaru®, rubberwood (GB, DE, MY, TH, IN), Gummibaumholz (DE), seringa, seringeira (BR), kayu karet (IN), arbol de caucho (sAm). Not protected under CITES regulations.
Tree. Geographic distribution: Indomalesia and tropical South America (cultivated in Indomalesia and Africa).
General. Growth ring boundaries distinct. Heartwood basically yellow and white or grey. Sapwood colour similar to heartwood colour. Density 0.52–0.6–0.64 g/cm³. With unpleasant odour when fresh.
Vessels. Vessels present. Wood diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows and radial rows of 4 or more (rarely up to 10). Average tangential vessel diameter 145–205–260 µm. Average number of vessels/mm² 1–3. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 10–12 µm, vestured. Vessel-ray pits with reduced borders or apparently simple, rounded or angular. Helical thickenings absent. Tyloses in vessels present, thinwalled. Other deposits in heartwood vessels present (brown).
Tracheids and fibres. Fibres of medium wall thickness. Fibre pits mainly restricted to radial walls, distinctly bordered. Fibres non-septate.
Axial parenchyma. Axial parenchyma banded. Axial parenchyma bands reticulate, fine, up to three cells wide. Axial parenchyma apotracheal. Apotracheal axial parenchyma diffuse-in-aggregates (in short tangential lines). Axial parenchyma as strands. Average number of cells per axial parenchyma strand 4–8.
Rays. Rays 8–12 per tangential mm, multiseriate (also if only few), 2–5 cells wide. Rays with multiseriate portions as wide as uniseriate portions rarely present, or absent. Rays composed of two or more cell types (heterocellular). Heterocellular rays with square and upright cells restricted to marginal rows, mostly 2–4 marginal rows of upright or square cells or with more than 4 marginal rows of upright or square cells.
Storied structures. Storied structure absent.
Secretory structures. Intercellular canals absent.
Cambial variants. Included phloem absent.
Mineral inclusions. Crystals present, prismatic, located in ray cells or axial parenchyma cells. Crystal-containing ray cells upright and/or square, upright and/or square ray cells chambered or not chambered. Crystals in procumbent ray cells not in radial alignment. Crystal-containing axial parenchyma cells chambered, or not chambered. Number of crystals per cell or chamber one, or more than one. Crystals in one cell or chamber of the same size, or of two distinct sizes. Crystal containing cells of normal size. Silica not observed.
Illustrations. • Macro images. Hevea brasiliensis. Transverse. Tangential. • Transverse section. Hevea brasiliensis. • Tangential section. Hevea brasiliensis. • Radial section. Hevea brasiliensis.
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. http://delta-intkey.com’.