Commercial Timbers


H. G. Richter and M. J. Dallwitz

Mezilaurus spp. (Itauba)

Nomenclature etc. LAURACEAE. M. itauba (Meissn.) Taub. ex Mez, M. lindaviana Schw. & Mez. Trade and local names: M. itauba: itaúba, i. preta, i. vermelha, i. amarela, louro itaúba (BR); M. lindaviana: itaúba abacate (BR). Not protected under CITES regulations.

Tree. Geographic distribution: tropical South America.

General. Heartwood basically brown to yellow brown to green. Sapwood colour distinct from heartwood colour. Density 0.65–0.75 g/cm³.

Vessels. Wood diffuse-porous. Vessels arranged in sometimes in diagonal pattern, yet mostly no specific pattern, in multiples, commonly short (2–3 vessels) radial rows or radial rows of 4 or more. Average tangential vessel diameter 80–120–190 µm. Average number of vessels/mm² 8–14–26. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 10–14(–16) µm. Vessel-ray pits with reduced borders or apparently simple, different from intervessel pits, rounded or angular or horizontal to vertical (large window-like pits), unilaterally compound and coarse. Tyloses in vessels present, thinwalled or sclerotic.

Tracheids and fibres. Fibres of medium wall thickness to very thick-walled. Average fibre length 900–1600–2200 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres septate and non-septate. Septate fibres evenly distributed.

Axial parenchyma. Axial parenchyma rarely apotracheal, or paratracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma vasicentric, confluent, and unilateral. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 2–8. Axial parenchyma often sclerotic.

Rays. Rays 4–11 per tangential mm, multiseriate (also if only few), 2–3(–4) cells wide. 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.

Secretory structures. Oil and mucilage cells present (oil cells), associated with axial parenchyma or ray parenchyma (infrequent). Oilcells conspicuous, barrel-shaped.

Mineral inclusions. Crystals not observed. Silica present, as grains, in rays cells. Silica particles located in short, 2–6 seriate strings of procumbent as well as square/upright cell; this feature is typical for Mezilaurus and sofar has not been observed in other taxa.

Physical and chemical tests. Splinter burns to charcoal.

Illustrations. • Macro images. Mezilaurus itauba. Transverse. Tangential. • Transverse section. Mezilaurus itauba. • Tangential section. Mezilaurus itauba. • Radial section. Mezilaurus itauba. • Silica in rays. Mezilaurus itauba. Silica particles located in rays, in series of 2 to 4 radially shortened cells, a feature unique to the lauraceous genera Mezilaurus and Clinostemon.

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.’.