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| Commercial timbers |
Nomenclature etc. BIXACEAE. Including Bixa orellana (shrub). Trade and local names: açafroa, açafroeira da terra, urucú, u. bravo, urucum (BR); arnato, achiote, bija, bixa, (sAm); annatto (GB); roucou (FR); Orlean-strauch (DE); lipstick tree (US);. Not protected under CITES regulations.
Tree, or shrub. Geographic distribution: Mexico and Central America, Caribbean, tropical South America.
General. Heartwood basically brown and yellow, white or grey. Sapwood colour similar to heartwood colour. Density 0.28–0.35 g/cm³. Wood of commercial potential, or of no commercial potential.
Vessels. Wood diffuse porous. Vessels in multiples, commonly in short (2–3 vessels) radial rows or in radial rows of 4 or more. Average tangential vessel diameter 90–150(–190) µm. Average number of vessels/mm² 4–8. Average vessel element length 340–430–630 µm. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 3–5 µm, pits vestured. Vessel-ray pits with distinct borders, similar to intervessel pits.
Tracheids and fibres. Vascular or vasicentric tracheids commonly present (vasicentric). Fibres very thin-walled. Average fibre length 720–1100–1900 µm. Fibre pits common in both radial and tangential walls, simple to minutely bordered or distinctly bordered.
Axial parenchyma. Apotracheal axial parenchyma diffuse. Axial parenchyma as strands. Average number of cells per strand: 2–4.
Rays. Rays 8–12 per tangential mm, multiseriate, 1–3 cells wide. Height of large rays up to 500 µm. 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. Perforated ray cells present. Rays contain perforated ray cells and horizontally oriented vascular elements, interspersed with parenchymateous cells (see Chalk & Chattaway 1933, Carlquist 1960, 1988).
Storied structures. Storied structure present, all rays storied, axial parenchyma storied, vessel elements storied, fibres storied. Arrangement of tiers regular, or irregular. Number of ray tiers per axial millimetre 3–4. Longitudinally fused rays extend over several stories.
Secretory structures. Intercellular canals absent.
Cambial variants. Occasionally with small groups of non-perforated vascular elements without contact to vessels, embedded between fibres and axial parenchyma strands.
Mineral inclusions. Crystals not observed. Silica not observed.
Illustrations. • Transverse section. • Tangential section. • Radial section.
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: 9th April 2019. delta-intkey.com’.
