Ochroma lagopus Sw. (Balsa)
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, D, USA, GB, F, NL), Tami (BOL), Topa (PE), Lano, Tacarigua (YV), Enea, Pung (CR), Gatillo, Polak (NIC), Guano (HON), Gonote, Maho (MEX), Corkwood (GUY), Cajeto, Tanbor (GUA).
Tree. Geographic distribution: Mexico and Central America, Caribbean, and tropical South America (widely cultivated in Africa and Asia).
General. Heartwood basically white or grey to brown (never dark coloured). Sapwood colour similar to heartwood colour. Basic specific gravity 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 rays square and upright cells restricted to marginal rows. Number of marginal rows of upright or square cells 1, or 2–4 (mostly 1–2 seriate). 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.
Cite this publication as: H. G. Richter and M. J. Dallwitz (2000 onwards). 'Commercial timbers: descriptions, illustrations, identification, and information retrieval.' In English, French, German, and Spanish. Version: 4th May 2000. http://biodiversity.uno.edu/delta/.
Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993 onwards, 1995 onwards, 1998) should also be cited (see General references).