Ochroma pyramidale

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Rosids
Cladus: Eurosids II
Ordo: Malvales

Familia: Malvaceae
Subfamilia: Bombacoideae
Genus: Ochroma
Species: Ochroma pyramidale
Name

Ochroma pyramidale (Cav. ex Lam.) Urb., Repert. Spec. Nov. Regni Veg. Beih. 5: 123. 1920.
Synonymy

Basionym
Bombax pyramidale Cav. ex Lam., Encycl. [J. Lamarck & al.] 2(2): 552. (Apr) 1788.

Homotypic
Bombax pyramidale Cav., Diss. 5: 294(–295), t. 153. (Jul) 1788, isonym
Bombax pyramidatum Steud., Nomencl. Bot. 1: 114. 1821, sphalm., pro syn.

Heterotypic
Ochroma lagopus Sw., Prodr.: 98. (Jun–Jul) 1788. (as Lagopus)
Ochroma tomentosum Humb. & Bonpl. ex Willd., Enum. Pl. 2: 695. 1809. (as Ochroma tomentosa)
Ochroma lagopodum St.-Lag., Ann. Soc. Bot. Lyon 7: 131. 1880, orth. var.
Bombax angulatum Sessé & Moc., Fl. Mexic., ed. 2: 154(–155). 1894. (as Angulata) – Fl. Mexic.: 169. 1895 [1896]. (as Angulata)
Ochroma concolor Rowlee, J. Wash. Acad. Sci. 9(6): 161(–162). 1919.
Typus: Guatemala, Alta Verapaz: Trece Aguas, on cacao plantation; 9 May 1914; O.F.Cook & C.B.Doyle 82 (holotype: US-00102061 [= 862345]).
Ochroma limonense Rowlee, J. Wash. Acad. Sci. 9(6): 163. 1919. (as Ochroma limonensis)
Ochroma grandiflorum Rowlee, J. Wash. Acad. Sci. 9(6): 163(–164). 1919. (as Ochroma grandiflora)
Ochroma velutinum Rowlee, J. Wash. Acad. Sci. 9(6): 164(–165). 1919. (Ochroma velutina)
Ochroma bicolor Rowlee, J. Wash. Acad. Sci. 9(6): 165(–166). 1919.
Ochroma bolivianum Rowlee, J. Wash. Acad. Sci. 9(6): 166. 1919. (as Ochroma boliviana)
Ochroma obtusum Rowlee, J. Wash. Acad. Sci. 9(6): 166(–167). 1919. (as Ochroma obtusa)
Ochroma peruvianum I.M.Johnst., Contr. Gray Herb. 81: 95. 1928. (as Ochroma peruviana)
Typus: Peru, Huánuco: Pampayacu, Rio Hullaga; 23 Jan 1927; R.Kanehira 354 (holotype: GH-00071937, GH-00071938).
Ochroma tomentosum var. ibarrense Benoist, Bull. Soc. Bot. France 88(2–3): 439. 1941. (as var. Ibarrensis)
Ochroma pyramidale var. concolor (Rowlee) R.E.Schult., Bot. Mus. Leafl. 9(9): 177(–179). 1941.
Ochroma lagopus var. bicolor (Rowlee) Standl. & Steyerm., Publ. Field Mus. Nat. Hist., Bot. Ser. 23(2): 62. 1944.
Ochroma lagopus var. occigranatense Cuatrec., Phytologia 4(8): 480. 1954. (as var. occigranatensis)
Typus: Colombia, Valle del Cauca: Cordillera Occidental, vertiente occidental: Hoya del río Digua, lado izquierdo: Piedra de Moler, alt. 900–1180 m; 25 Aug 1943; Cuatrecasas 15143 (holotype: F-0052157F, F-0052158F, F-0052159F, F-0052160F; isotypes: COL-000002457, COL-000002458).
Ochroma pyramidale var. bicolor (Rowlee) Brizicky in Brizicky et al., Trop. Woods 109: 63(–64). 1958.

Distribution
Native distribution areas:

Northern America
Mexico
Mexico Gulf, Mexico Southeast, Mexico Southwest.
Southern America
Central America
Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama.
Caribbean
Cuba, Dominican Republic, Haiti, Jamaica, Leeward Is., Puerto Rico, Trinidad-Tobago, Windward Is.
Northern South America
French Guiana, Guyana, Venezuela.
Western South America
Bolivia, Colombia, Ecuador, Peru.
Brazil
Brazil North.

References: Brummitt, R.K. 2001. TDWG – World Geographical Scheme for Recording Plant Distributions, 2nd Edition
References
Primary references

Benoist, R. 1941. Plantes récoltées dans la République de l’Equateur. Bulletin de la Société Botanique de France 88: 431–439. DOI: 10.1080/00378941.1941.10834246 Biblioteca Digital Reference page.
Brizicky, G.K., Stern, W.L. & Chambers, K.L. 1958. A collection of woody plants from Panama. Tropical Woods 109: 61–80. PDF Reference page.
Cavanilles, A.I. 1788. Quinta dissertatio botanica. De Sterculia, Kleinhovia, Ayenia, Buttneria, Bombace, Adansonia, Crinodendro, Aytonia, Malachodendro, Stewartia et Napaea. Accedit praecedentium dissertationum Mantissa. Pp. 267–304, tt. 125–159 in Monadelphiae classis dissertationes decem. Apud Franciscum Amb. Didot, Parisiis [Paris]. BHL Biblioteca Digital Reference page.
Cuatrecasas, J. 1954. Novelties in the Bombacaceae. Phytologia 4: 465–480. BHL Reference page.
Johnston, I.M. 1928. Some undescribed American spermatophytes. Contributions from the Gray Herbarium of Harvard University 81: 85–98. JSTOR Hybrid open access journal BHL Reference page.
Lamarck, J.-B. 1786–1788. Encyclopédie méthodique. Botanique. Tome 2. 774 pp. Panckoucke, Paris; Plomteux, Liége. BHL Reference page.
Rowlee, W.W. 1919. Synopsis of the genus Ochroma, with descriptions of new species. Journal of the Washington Academy of Sciences 9: 157–167. BHL. Reference page.
Saint-Lager, J.B. 1880. Réforme de la nomenclature botanique. Annales de la Société Botanique de Lyon 7: 1–154. BHL Reference page.
Schultes, R.E. 1941. Plantae mexicanae X. New or critical species from Oaxaca. Botanical Museum Leaflets 9: 165–198, tt. I–IX. BHL JSTOR Reference page.
Sesse, M. & Mociño, I.M. 1891–1897 ["1887"]. Flora Mexicana. XI+263+XVI pp. Apud Ignatius Escalante, Mexici [Mexico]. BHL Reference page.
Sesse, M. & Mociño, J.M. 1894. Flora Mexicana. Editio secunda. XI+240+XXII pp. Oficina Tipográfica de la Secretaría de Fomento, México. BHL Reference page.
Standley, P.C. & Steyermark, J.A. 1944. Studies of Central American plants—IV. Publications of the Field Museum of Natural History, Botanical Series 23: 29–109. BHL Reference page.
Steudel, E. 1821. Nomenclator botanicus enumerans ordine alphabetico nomina atque synonyma tum generica tum specifica et a Linnaeo et recentioribus de re botanica scriptoribus plantis phanerogamis imposita. Vol. 1. XVII+900 pp. Sumtibus I. G. Cottae, Stuttgardtiae [Stuttgart] & Tubingae [Tübingen]. BHL Reference page.
Swartz, O. 1788. Nova genera & species plantarum seu Prodromus descriptionum vegetabilium, maximam partem incognitorum quae sub itinere in Indiam Occidentalem annis 1783–87 digessit Olof Swartz. M. D. X+152 pp., index. M.Swederi, Holmiae [Stockholm] etc. BHL Reference page.
Urban, I. 1920. Plumiers Leben und Schriften nebst einem Schlüssel zu seinen Blütenpflanzen. Repertorium Specierum Novarum Regni Vegetabilis. Beihefte 5: 1–196. BHL Reference page.
Willdenow, C.L. 1809. Enumeratio plantarum horti regii botanici berolinensis, continens descriptiones omnium vegetabilium in horto dicto cultorum. VI + 1099 pp. In taberna Libraria Scholae realis, Berolini [Berlin]. BHL Biblioteca Digital Reference page.

Additional references

Alverson, W.S., Dorr, L.J. & Steyermark, J.A. (†) 2007. Bombacaceae. In Funk, V., Hollowell, T., Berry, P., Kelloff, C. & Alexander, S.N., Checklist of the plants of the Guiana Shield (Venezuela: Amazonas, Bolivar, Delta Amacuro; Guyana, Surinam, French Guiana). Contributions from the United States National Herbarium 55: 220–223. BHL Reference page.
Alverson, W.S. & Steyermark, J.A. (†). 1997. Bombacaceae. Pp. 496–527 in Steyermark, J.A., Berry, P.E. & Holst, B.K. (eds.), Flora of the Venezuelan Guayana, Vol. 3, Araliaceae–Cactaceae. Missouri Botanical Garden, St. Louis. ISBN 0-915279-46-0. Reference page.
Avendaño Reyes, S. 1998. Bombacaceae. In Flora de Veracruz, Fasc. 107. 40 pp. Instituto de Ecología, A.C. Xalapa, Veracruz; University of California, Riverside, CA, USA. ISBN 968-7863-29-3. PDF Reference page.
DeFilipps, R. 1991. Bombacaceae. In Nicolson, D.H., Flora of Dominica, Part 2: Dicotyledoneae. Smithsonian Contributions to Botany 77: 52–53. BHL Reference page.
Dorr, L.J. 2012. Malvaceae. In Acevedo-Rodríguez, P. & Strong, M.T., Catalogue of seed plants of the West Indies. Smithsonian Contributions to Botany 98: 496–529. BHL Reference page.
Fawcett, W. & Rendle, A.B. 1926. Family LXV. Bombacaceae. Pp. 149–154 in Flora of Jamaica, containing descriptions of the flowering plants known from the Island, Vol. 5, Dicotyledons, families Buxaceae to Umbelliferae. British Museum, London. BHL Reference page.
Fournet, J. 2002. 51. Bombacaceae. Pp. 352–358 in Flore illustrée des phanérogames de Guadeloupe et de Martinique, Tome 1, Nouv. éd. CIRAD, Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Montpellier. ISBN 2-908490-26-9. Reference page.
Gentry, A.H. & Alverson, W.S. 2001. Bombacaceae Kunth. Pp. 430–435 in Stevens, W.D., Ulloa Ulloa, C., Pool, A. & Montiel, O.M. (eds.), Flora de Nicaragua, Vol. 1, Introducción, gimnospermas y angiospermas (Acanthaceae–Euphorbiaceae). (Monographs in Systematic Botany from the Missouri Botanical Garden 85). Missouri Botanical Garden Press, St. Louis. ISBN 0-915279-95-9. Online Reference page.
Liogier, A.H. 1982. Familia Bombacaceae. Pp. 178–189 in La Flora de la Española. I. Universidad Central del Este, San Pedro de Macorís, República Dominicana. Reference page. (as Ochroma lagopus)
Liogier, H.A. 1994. Family 76.– Bombacaceae. Pp. 173–185 in Descriptive Flora of Puerto Rico and adjacent islands. Spermatophyta. Vol. III Cyrillaceae to Myrtaceae. Editorial de la Universidad de Puerto Rico, Río Piedras, Puerto Rico. ISBN 0-8477-2336-4 Reference page.
Macbride, J.F. 1956. Bombacaceae. In Flora of Peru. Publications of the Field Museum of Natural History, Botanical Series 13(3A/2): 593–622. BHL Reference page. (as Ochroma lagopus)
Robyns, A. 1964. Family 116. Bombacaceae. In Woodson, R.E., Jr., Schery, R.W. & Collaborators, Flora of Panama, Part VI. Annals of the Missouri Botanical Garden 51: 37–68. DOI: 10.2307/2394901 BHL JSTOR Reference page.
Standley, P.C. & Record, S.J. 1936. Bombacaceae. In The forests and flora of British Honduras. Publications of the Field Museum of Natural History, Botanical Series 12: 247–251. BHL Reference page. (as Ochroma concolor & O. limonensis)
Standley, P.C. & Steyermark, J.A. 1949. Bombacaceae. In Flora of Guatemala – Part VI. Fieldiana: Botany 24(6): 386–403. BHL Reference page. (as Ochroma lagopus)
Villaseñor, J.L. 2016. Checklist of the native vascular plants of Mexico. Revista Mexicana de Biodiversidad 87: 559–902. DOI: 10.1016/j.rmb.2016.06.017 Online PDF Reference page.

Links

International Plant Names Index. 2018. Ochroma pyramidale. Published online. Accessed: 30 March 2018.
Global Biodiversity Information Facility. 2019. GBIF Backbone Taxonomy. Checklist dataset. Taxon: Ochroma pyramidale.
USDA, ARS, Germplasm Resources Information Network. Ochroma pyramidale in the Germplasm Resources Information Network (GRIN), U.S. Department of Agriculture Agricultural Research Service. Accessed: 2018-03-30.
Hassler, M. 2018. Ochroma pyramidale. World Plants: Synonymic Checklists of the Vascular Plants of the World In: Roskovh, Y., Abucay, L., Orrell, T., Nicolson, D., Bailly, N., Kirk, P., Bourgoin, T., DeWalt, R.E., Decock, W., De Wever, A., Nieukerken, E. van, Zarucchi, J. & Penev, L., eds. 2018. Species 2000 & ITIS Catalogue of Life. Published online. Accessed: 2018 June 22. Reference page.

Tropicos.org 2018. Ochroma pyramidale. Missouri Botanical Garden. Published online. Accessed: 30 March 2018.
Tropicos.org: Flora Mesoamericana: Ochroma pyramidale. Missouri Botanical Garden. Published online. Accessed: 30 March 2018.
Ochroma pyramidale in Bernal, R., Gradstein, S.R. & Celis, M. (eds.). 2015. Catálogo de plantas y líquenes de Colombia. Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá. Accessed: 14 April 2018.
Tropicos.org: Catalogue of the Vascular Plants of the Department of Antioquia (Colombia): Ochroma pyramidale. Missouri Botanical Garden. Published online. Accessed: 30 March 2018.
Tropicos.org: Catalogue of the Vascular Plants of Ecuador: Ochroma pyramidale. Missouri Botanical Garden. Published online. Accessed: 30 March 2018.
Tropicos.org: Peru Checklist: Ochroma pyramidale. Missouri Botanical Garden. Published online. Accessed: 30 March 2018.
Tropicos.org: Bolivia Catalogue: Ochroma pyramidale. Missouri Botanical Garden. Published online. Accessed: 30 March 2018.
Ochroma pyramidale in Flora do Brasil 2020 em construção. Jardim Botânico do Rio de Janeiro. Accessed: 12 April 2018.

Vernacular names
Deutsch: Balsabaum
English: Balsa
suomi: Balsapuu
français: Balsa
Nederlands: Balsaboom
slovenščina: Balzovec
svenska: Balsa
Türkçe: Balsa

Ochroma pyramidale, commonly known as the balsa tree, is a large, fast-growing tree native to the Americas. It is the sole member of the genus Ochroma.[1] The tree is famous for its wide usage in woodworking, with the name balsa being the Spanish word for "raft."[3]

A deciduous angiosperm, Ochroma pyramidale can grow up to 30 m tall, and is classified as a hardwood despite the wood itself being very soft; it is the softest commercial hardwood and is widely used because of its light weight.

Biology
Balsa on Bota Hill, Limbe Botanical Garden, Cameroon

A member of the mallow family, Ochroma pyramidale is native from southern Mexico to southern Brazil, but can now be found in many other countries (Papua New Guinea, Indonesia, Thailand, Solomon Islands). It is a pioneer plant, which establishes itself in clearings in forests, either man-made or where trees have fallen, or in abandoned agricultural fields. It grows extremely rapidly, up to 27 metres (89 ft) in 10–15 years. The speed of growth accounts for the lightness of the wood, which has a lower density than cork. Trees generally do not live beyond 30 to 40 years.[4]

Flowers are produced from the third year onwards, typically at the end of the rainy season when few other trees are in flower. The large flowers open in the late afternoon and remain open overnight. Each may contain a pool of nectar up to 2.5 centimetres (0.98 in) deep. Daytime pollinators include capuchin monkeys. However, most pollination occurs at night. The main pollinators were once thought to be bats, but recent evidence suggests that two nocturnal arboreal mammals, the kinkajou and the olingo, may be the primary pollinators.[4]

It is evergreen or dry-season deciduous, with large 30 to 40 centimetres (12 to 16 in), weakly palmately lobed leaves.

Being a deciduous angiosperm, balsa is classified as a hardwood despite the wood itself being very soft; it is the softest commercial hardwood.
Cultivation

Ecuador supplies 95% or more of commercial balsa. In recent years, about 60% of the balsa has been plantation-grown in densely packed patches of around 1000 trees per hectare (compared to about two to three per hectare in nature). The trees are harvested after six to ten years of growth.
Uses
Three different sizes of balsa wood stock

Balsa lumber is very soft and light, with a coarse, open grain. The density of dry balsa wood ranges from 40 to 340 kg/m3, with a typical density around 160 kg/m3.[5][6][7] Balsa is the softest wood ever measured using the Janka hardness test (22 to 167 lbf).[8] The wood of the living tree has large cells that are filled with water. This gives the wood a spongy texture. It also makes the wood of the living tree not much lighter than water and barely able to float. For commercial production, the wood is kiln-dried for about two weeks, leaving the cells hollow and empty. The large volume-to-surface ratio of the resulting thin-walled, empty cells gives the dried wood a large strength-to-weight ratio because the cells are mostly air. Unlike naturally rotted wood, which soon disintegrates in the rainforests where balsa trees grow, the cell walls of kiln-seasoned balsa wood retain their strong structure of cellulose and lignin.[9]

Because it is low in density but high in strength, balsa is a very popular material for light, stiff structures in model bridge tests, model buildings, and construction of model aircraft; all grades are usable for airworthy control line and radio-controlled aircraft varieties of the aeromodeling sports, with the lightest "contest grades" especially valuable for free-flight model aircraft. However, it is also valued as a component of full-sized light wooden aeroplanes, most notably the World War II de Havilland Mosquito.[9]

Balsa is used to make wooden crankbaits for fishing, especially Rapala lures.

Sticks of dried balsa are useful as makeshift pens for calligraphy when commercial metal nibs of the desired width are not available.

Balsa wood is often used as a core material in composites; for example, the blades of many wind turbines are partly of balsa. In table tennis bats, a balsa layer is typically sandwiched between two pieces of thin plywood made from other species of wood. Balsa wood is also used in laminates together with glass-reinforced plastic (fiberglass) for making high-quality balsa surfboards and for the decks and topsides of many types of boats, especially pleasure craft less than 30 m in length. On a boat, the balsa core is usually end-grain balsa, which is much more resistant to compression than if the soft balsa wood were laid lengthwise.

Balsa is also used in the manufacture of "breakaway" wooden props such as tables and chairs that are designed to be broken as part of theatre, movie, and television productions.

The fifth and sixth generations of the Chevrolet Corvette had floor pans composed of balsa sandwiched between sheets of carbon-fiber-reinforced plastic.[9]

Norwegian scientist and adventurer Thor Heyerdahl, convinced that early contact between the peoples of South America and Polynesia was possible, built the raft Kon Tiki from balsa logs, and upon it his crew and he sailed the Pacific Ocean from Peru to the Polynesian Tuamotu Archipelago in 1947. However, the Kon Tiki logs were not seasoned and owed much of their (rather slight) buoyancy to the fact that their sap was of lower density than sea water. This serendipitously may have saved the expedition, because it prevented the seawater from waterlogging the wood and sinking the raft.[10]

Balsa wood is also a popular wood type used in the arts of whittling,[9] and surfing. In the making of picture frames, balsa was often used in a baroque style because of the ease of shaping the design.