Commercial Timbers


H. G. Richter and M. J. Dallwitz

Simarouba amara Aubl. (Simaruba, marupá)

Nomenclature etc. SIMAROUBACEAE. Trade and local names: marupá , caixeta, cajú-rana, malacacheta, pitomba (BR), hualaja (PE), soemaroepa (SR, NL), simaruba (DE, GB, VE), acajou blanc (GF, FR), bitterwood (US). Not protected under CITES regulations.

Tree. Geographic distribution: tropical South America.

General. Heartwood basically yellow to white or grey, without streaks. Sapwood colour similar to heartwood colour. Density 0.32–0.4 g/cm³.

Vessels. Wood diffuse-porous. Vessels in multiples, commonly short (2–3 vessels) radial rows. Average tangential vessel diameter 130–200–290 µm. Average number of vessels/mm² 1–4(–10). Average vessel element length 3–720 µm. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 6–8 µm. Vessel-ray pits with distinct borders, similar to intervessel pits. Helical thickenings absent. Other deposits in heartwood vessels present (yellowish brown).

Tracheids and fibres. Fibres very thin-walled. Average fibre length 770–1150–1590 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres non-septate.

Axial parenchyma. Axial parenchyma not banded. Axial parenchyma paratracheal. Paratracheal axial parenchyma aliform and confluent. Aliform parenchyma winged. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 3–7.

Rays. Rays 3–8 per tangential mm, multiseriate (also if only few), (2–)3–5 cells wide. Rays of one size. Rays composed of a single cell type (homocellular), or 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. Sheath cells absent. Few heterocelular rays.

Storied structures. Storied structure present, all rays storied, axial parenchyma storied, vessel elements storied, fibres storied. Arrangement of tiers regular (horizontal or straight), or irregular. Number of ray tiers per axial millimetre 2.

Secretory structures. Intercellular canals present (of sporadic occurrence), traumatic origin (?), axial type, in long tangential lines.

Mineral inclusions. Crystals present, prismatic, located in rarely ray cells or axial parenchyma cells. Crystal-containing ray cells procumbent. Crystal-containing axial parenchyma cells chambered, or not chambered. Number of crystals per cell or chamber one. Silica not observed.

Illustrations. • Macro images. Simarouba amara. Transverse. Radial. • Transverse section. Simarouba amara. • Tangential section. Simarouba amara. • Radial section. Simarouba amara.

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.’.