Virola

Virola spp. (Virola, bicuiba)

Nomenclature etc. MYRISTICACEAE. V. carinata, V. cuspidata, V. elongata, V. flexuosa, V. gardneri, V. kukachkana, V. michelii, V. multicostata, V. pavonis, V. sebifera, V. surinamensis. Trade and local names: Bicuiba, bucuva, bucuvcú (BR); sebo, otobo, nu namo (COL); virola

Tree. Geographic distribution: tropical South America to southern Brazil.

General. Heartwood basically pinkish brown red. Sapwood colour similar to heartwood colour. Basic specific gravity 0.4–0.65 g/cm³ (V. carinata 0.70–0.75).

Vessels. Vessels present. Wood diffuse-porous. Vessels in multiples, commonly short (2–3 vessels) radial rows. Average tangential vessel diameter 90–160 µm (140–200 in V. kukachkana, V. surinamensis). Average number of vessels/mm² 6–12 (2–5 in V. kukachkana, V. surinamensis). Perforation plates predominantly simple (rarely) or scalariform, with (1–)3–8 bars. Irregular, reticulate perforation plates can also be observed occasionally; diagnostically insignificant. Intervessel pits alternate, average diameter (vertical) 8–12 µm. Vessel-ray pits with reduced borders or apparently simple, rounded or
angular or horizontal to vertical. Tyloses in vessels present (sporadically), thinwalled.

Tracheids and fibres. Fibres very thin-walled, or of medium wall thickness. Average fibre length 1200–1800 µm (V. surinamensis). Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres septate and non-septate, or non-septate. Septate fibres scattered near vessels and rays.

Axial parenchyma. Axial parenchyma banded or not banded. Axial parenchyma bands marginal (or seemingly marginal), fine, up to three cells wide. Axial parenchyma paratracheal. Paratracheal axial parenchyma scanty. Axial parenchyma as
strands. Average number of cells per axial parenchyma strand 4–10.

Rays. Rays 5–9 per tangential mm, multiseriate, also if only few, (1–)2 cells wide. Rays composed of two or more cell types. Heterocellular rays square and upright cells restricted to marginal rows. Number of marginal rows of upright or square
cells 1, or 2–4.

Secretory structures. Oil and mucilage cells absent. Intercellular canals absent. Laticifers or tanniniferous tubes present.

Mineral inclusions. Crystals not observed. Silica not observed.