''Ochroma pyramidale'', commonly known as the balsa tree, is a large, fast-growing
tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...
native to the Americas. It is the sole member of the
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
''Ochroma''.
The tree is famous for its wide usage in
woodworking
Woodworking is the skill of making items from wood, and includes cabinet making (cabinetry and furniture), wood carving, joinery, carpentry, and woodturning.
History
Along with stone, clay and animal parts, wood was one of the first mate ...
, with the name ''balsa'' being the Spanish word for "raft."
A deciduous
angiosperm
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants ...
, ''Ochroma pyramidale'' can grow up to 30 m tall, and is classified as a
hardwood
Hardwood is wood from dicot trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen. Hardwood (which comes from ...
despite the wood itself being very soft; it is the softest commercial hardwood and is widely used because of its light weight.
Biology
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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 in 10–15 years. The speed of growth accounts for the lightness of the wood, which has a lower density than
cork
Cork or CORK may refer to:
Materials
* Cork (material), an impermeable buoyant plant product
** Cork (plug), a cylindrical or conical object used to seal a container
***Wine cork
Places Ireland
* Cork (city)
** Metropolitan Cork, also known as G ...
. Trees generally do not live beyond 30 to 40 years.
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 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
The genus ''Bassaricyon'' consists of small Neotropical procyonidae, procyonids, popularly known as olingos (), cousins of the raccoon. They are native to the rainforests of Central America, Central and South America from Nicaragua to Peru. They ...
, may be the primary pollinators.
[
It is ]evergreen
In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, whic ...
or dry-season deciduous
In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, ...
, with large , weakly palmately
The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular ...
lobed leaves.
Being a deciduous angiosperm
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants ...
, balsa is classified as a hardwood
Hardwood is wood from dicot trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen. Hardwood (which comes from ...
despite the wood itself being very soft; it is the softest commercial hardwood.
Cultivation
Ecuador
Ecuador ( ; ; Quechua: ''Ikwayur''; Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechua: ''Ikwadur Ripuwlika''; Shuar: ' ...
supplies 95% or more of commercial balsa. In recent years, about 60% of the balsa has been plantation
A plantation is an agricultural estate, generally centered on a plantation house, meant for farming that specializes in cash crops, usually mainly planted with a single crop, with perhaps ancillary areas for vegetables for eating and so on. Th ...
-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
Balsa lumber
Lumber is wood that has been processed into dimensional lumber, including beams and planks or boards, a stage in the process of wood production. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, w ...
is very soft and light, with a coarse, open grain
A grain is a small, hard, dry fruit ( caryopsis) – with or without an attached hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and legum ...
. The density
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematicall ...
of dry balsa wood
Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin ...
ranges from 40 to 340 kg/m3, with a typical density around 160 kg/m3. Balsa is the softest wood ever measured using the Janka hardness test (22 to 167 lbf). 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 rainforest
Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...
s where balsa trees grow, the cell walls of kiln-seasoned
Seasoning is the process of supplementing food via herbs, spices, salts, and/or sugar, intended to enhance a particular flavour.
General meaning
Seasonings include herbs and spices, which are themselves frequently referred to as "seasonings". Ho ...
balsa wood retain their strong structure of cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wa ...
and lignin
Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity a ...
.
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 aeroplane
An airplane or aeroplane (informally plane) is a fixed-wing aircraft that is propelled forward by thrust from a jet engine, propeller, or rocket engine. Airplanes come in a variety of sizes, shapes, and wing configurations. The broad spec ...
s, most notably the World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...
de Havilland Mosquito
The de Havilland DH.98 Mosquito is a British twin-engined, shoulder-winged, multirole combat aircraft, introduced during the World War II, Second World War. Unusual in that its frame was constructed mostly of wood, it was nicknamed the "Wooden ...
.
Balsa is used to make wooden crankbaits for fishing, especially Rapala
Rapala ( ) is a manufacturer of fishing lures and other fishing related products. It was founded in Finland in 1936 by Lauri Rapala, who is credited for creating the world's first floating minnow lure carved from cork with a shoemaker's kni ...
lures.
Sticks of dried balsa are useful as makeshift pens for calligraphy
Calligraphy (from el, link=y, καλλιγραφία) is a visual art related to writing. It is the design and execution of lettering with a pen, ink brush, or other writing instrument. Contemporary calligraphic practice can be defined ...
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 turbine
A wind turbine is a device that converts the kinetic energy of wind into electrical energy. Hundreds of thousands of large turbines, in installations known as wind farms, now generate over 650 gigawatts of power, with 60 GW added each year. ...
s are partly of balsa. In table tennis
Table tennis, also known as ping-pong and whiff-whaff, is a sport in which two or four players hit a lightweight ball, also known as the ping-pong ball, back and forth across a table using small solid rackets. It takes place on a hard table div ...
bats, a balsa layer is typically sandwiched between two pieces of thin plywood
Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured ...
made from other species of wood. Balsa wood is also used in laminate
Lamination is the technique/process of manufacturing a material in multiple layers, so that the composite material achieves improved strength, stability, sound insulation, appearance, or other properties from the use of the differing materia ...
s together with glass-reinforced plastic
Fiberglass (American English) or fibreglass (Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass clo ...
(fiberglass
Fiberglass ( American English) or fibreglass (Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cl ...
) for making high-quality balsa surfboard
A surfboard is a narrow plank used in surfing. Surfboards are relatively light, but are strong enough to support an individual standing on them while riding an ocean wave. They were invented in ancient Hawaii, where they were known as ''papa he'e ...
s and for the decks and topsides of many types of boat
A boat is a watercraft of a large range of types and sizes, but generally smaller than a ship, which is distinguished by its larger size, shape, cargo or passenger capacity, or its ability to carry boats.
Small boats are typically found on i ...
s, 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 pan
The floorpan is a large sheet metal stamping that often incorporates several smaller welded stampings to form the floor of a large vehicle and the position of its external and structural panels.
In the case of monocoque designs, the floorpa ...
s composed of balsa sandwiched between sheets of carbon-fiber-reinforced plastic
Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers ( Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon comp ...
.
Norwegian scientist and adventurer Thor Heyerdahl
Thor Heyerdahl KStJ (; 6 October 1914 – 18 April 2002) was a Norwegian adventurer and ethnographer with a background in zoology, botany and geography.
Heyerdahl is notable for his ''Kon-Tiki'' expedition in 1947, in which he sailed 8,000& ...
, convinced that early contact between the peoples of South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sou ...
and Polynesia
Polynesia () "many" and νῆσος () "island"), to, Polinisia; mi, Porinihia; haw, Polenekia; fj, Polinisia; sm, Polenisia; rar, Porinetia; ty, Pōrīnetia; tvl, Polenisia; tkl, Polenihia (, ) is a subregion of Oceania, made up of ...
was possible, built the raft '' Kon Tiki'' from balsa logs, and upon it his crew and he sailed the Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the conti ...
from Peru
, image_flag = Flag of Peru.svg
, image_coat = Escudo nacional del Perú.svg
, other_symbol = Great Seal of the State
, other_symbol_type = National seal
, national_motto = "Firm and Happy f ...
to the Polynesian Tuamotu Archipelago
The Tuamotu Archipelago or the Tuamotu Islands (french: Îles Tuamotu, officially ) are a French Polynesian chain of just under 80 islands and atolls in the southern Pacific Ocean. They constitute the largest chain of atolls in the world, extendin ...
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.
Balsa wood is also a popular wood type used in the arts of whittling, and surfing
Surfing is a surface water sport in which an individual, a surfer (or two in tandem surfing), uses a board to ride on the forward section, or face, of a moving wave of water, which usually carries the surfer towards the shore. Waves suitable ...
. In the making of picture frames, balsa was often used in a baroque style because of the ease of shaping the design.
Gallery
file:Ochroma pyramidale1FrancesWHorne.jpg, Painting by Frances W. Horne from the Flora Borinqueña
file:Ochroma pyramidale Maui.jpg, ''Ochroma pyramidale'' at Tropical Gardens of Maui Iao Valley
Iao Valley ( Hawaiian: ''Īao'': "cloud supreme", pronounced similar to "EE-yow") is a lush, stream-cut valley in West Maui, Hawaii, located west of Wailuku. Because of its natural environment and history, it has become a tourist location. It ...
Rd, Maui
The island of Maui (; Hawaiian: ) is the second-largest of the islands of the state of Hawaii at 727.2 square miles (1,883 km2) and is the 17th largest island in the United States. Maui is the largest of Maui County's four islands, whic ...
file:Balsas_and_kayak.jpg, Two balsa rafts and a kayak at Lagos de Montebello in Chiapas, Mexico
Chiapas (; Tzotzil and Tzeltal: ''Chyapas'' ), officially the Free and Sovereign State of Chiapas ( es, Estado Libre y Soberano de Chiapas), is one of the states that make up the 32 federal entities of Mexico. It comprises 124 municipalities ...
file:Balsa airframe.jpg, Balsa construction in a Paul K. Guillow, Inc.
Paul K. Guillow, Inc., commonly known as Guillow's, is an American manufacturer of balsa wood model aircraft kits.
The company was founded by Paul K. Guillow in 1926 in Wakefield, Massachusetts, and was originally called NuCraft Toys.
F ...
"stick and tissue" free-flight rubber scale model airplane
See also
* ''Tilia
''Tilia'' is a genus of about 30 species of trees or bushes, native throughout most of the temperate Northern Hemisphere. The tree is known as linden for the European species, and basswood for North American species. In Britain and Ireland they ...
'', another tree producing lightweight lumber (especially ''Tilia americana
''Tilia americana'' is a species of tree in the family Malvaceae, native to eastern North America, from southeast Manitoba east to New Brunswick, southwest to northeast Oklahoma, southeast to South Carolina, and west along the Niobrara River to ...
'')
* '' Paulownia''
References
External links
*
{{Taxonbar, from1=Q12302824, from2=Q187941
Bombacoideae
Malvaceae genera
Monotypic Malvales genera
Plants described in 1920
Trees of Mexico
Trees of Central America
Trees of Peru
Trees of South America
Trees of the Caribbean