Nomenclature etc. BOMBACACEAE. Syn.: O. pyramidale Urb., O. boliviana Rowlee, O. bicolor Rowlee, O. concolor Rowlee, O. grandiflora Rowlee, O. limonensis Rowlee, O. obtusa Rowlee, O. peruviana Johnston, O. velutina Rowlee. Trade and local names: balsa (cAm, sAm, DE, US, GB, FR, NL); tami (BO); topa (PE); lano, tacarigua (VE); enea, pung (CR); gatillo, polak (NI); guano (HN); gonote, maho (MX); corkwood (GY); cajeto, tanbor (GT). Not protected under CITES regulations.
Tree. Geographic distribution: Mexico and Central America, Caribbean, and tropical South America (cultivated in Africa and Asia).
General. Heartwood basically white or grey to brown (never dark coloured). Sapwood colour similar to heartwood colour. Density 0.1–0.2(–0.4) g/cm³.
Vessels. Wood diffuse-porous. Vessels in multiples, commonly short (2–3 vessels) radial rows. Average tangential vessel diameter 130–215–260 µm. Average number of vessels/mm² 1–2. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 7–9 µm. Vessel-ray pits with reduced borders or apparently simple, rounded or angular.
Tracheids and fibres. Fibres very thin-walled. Average fibre length 1690–2170–3600 µm. Fibre pits common in both radial and tangential walls.
Axial parenchyma. Axial parenchyma apotracheal and paratracheal. Apotracheal axial parenchyma diffuse. Paratracheal axial parenchyma scanty to vasicentric. Axial parenchyma fusiform and as strands. Average number of cells per axial parenchyma strand 2–4(–8).
Rays. Rays 2–4 per tangential mm, multiseriate (also if only few), (1–)3–7(–10) 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 or mostly 2–4 marginal rows of upright or square cells (mostly 1–2 marginal rows). Sheath cells present. Tile cells present (only cells higher than the procumbent cells = 'Pterospermum' type).
Mineral inclusions. Crystals extremely rare present, druses, located in ray cells. Druses were observed only spradically but are frequently mentioned in literature. Silica not observed.
Illustrations. • Tree. Ochroma lagopus. Ochroma lagopus. Ochroma lagopus. • Macro images. Ochroma lagopus. Transverse. Radial. • Transverse section. Ochroma lagopus. • Tangential section. Ochroma lagopus. • Radial section. Ochroma lagopus.
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’.