PlantaeHighest rank in taxonomy. Groups all life into domains: Animalia, Plantae, Fungi, etc.IUCN LCInternational Union for Conservation of Nature — the world authority on species extinction risk, using standardized criteria. — Least Concern — widespread and abundant; not at immediate risk of extinction.In ProgressCurrent stage of this record in the editorial review workflow. Recent Sighting
Ochroma pyramidale
Balsa Tree
(Cav. ex Lam.) Urb., 1920
Detailed Texts Multi-lang
The balsa tree (Ochroma pyramidale) is a medium to large deciduous pioneer tree belonging to the Malvaceae family (formerly classified in Bombacaceae). It is world-renowned for producing the lightest and softest commercial wood in existence. It grows at a breakneck speed, reaching up to 30 meters (100 feet) in height in less than 15 years. It is characterized by a smooth, light gray trunk, often with small buttresses at the base, and immense, heart-shaped or slightly lobed leaves (up to 40 cm across). Its spectacular, nocturnal, cup-shaped flowers are creamy-white, very large, and robust. The fruit is an elongated capsule that, upon maturing and splitting open, releases large quantities of a light brown, cottony fiber (balsa wool or kapok) that envelops the seeds. Its native distribution extends from southern Mexico to Bolivia and southern Brazil. In Costa Rica, it is an unmistakable tree of the low and middle elevations, frequently visible along roadsides and riverbanks.
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Julia Trouin
TaxonomyBiological classification ranks placing this species within the tree of life, from Kingdom down to Genus.
PhylumRank below Kingdom. Groups organisms sharing a fundamental body plan (e.g., Chordata = vertebrates and some invertebrates).Tracheophyta
ClassRank below Phylum. Subdivides by structural traits (e.g., Mammalia, Aves, Reptilia, Insecta).Magnoliopsida
OrderRank below Class. Groups related families sharing common ancestry (e.g., Carnivora, Primates).Malvales
FamilyRank below Order. Groups closely related genera (e.g., Felidae = cats, Canidae = dogs).Malvaceae
GenusRank just above Species. The first word in the two-part binomial scientific name.Ochroma
Taxonomic AuthorityThe scientist who first formally described and published this species, followed by the year of publication.(Cav. ex Lam.) Urb., 1920
Record Completeness
91%Coming soon
Ecology & StatusHow this species lives: habitat preferences, diet, behavior, population status, and role in its ecosystem.
OriginWhether the species is native (evolved here), endemic (found only here), or introduced by human activity.
Native
Population TrendDirection of change in population size over time: increasing, stable, decreasing, or unknown.
Stable
Trophic RolePosition in the food chain: producer, herbivore, carnivore, omnivore, decomposer, or parasite.
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Growth HabitPhysical form and structure of the plant: tree, shrub, herb, vine, epiphyte, aquatic, etc.
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Leaf TypeLeaf characteristics: deciduous (seasonal shed), evergreen, simple, compound, needle-like, etc.
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Flowering SeasonTime of year when this species typically reproduces or flowers.
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Recent SightingsWhether this species has been observed in the wild in Costa Rica within recent years.
Yes
Habitat SummaryOverview of the specific ecosystems and environments where this species is found in Costa Rica. Multi-lang
It is the quintessential light-demanding pioneer species. It is never found in the dark understory of closed primary forests. Instead, it rapidly colonizes forest clearings created by natural tree falls, landslides, flood-prone riverbanks, roadsides, and abandoned agricultural lands. It thrives in humid and very humid tropical climates, from sea level up to about 1,000 meters (3,300 feet) in elevation. It requires continuous full sun and high rainfall, although well-drained soil is preferred. It is one of the first trees to appear after a jungle is deforested, marking the beginning of secondary ecological succession.Light & Water NeedsSunlight intensity and moisture levels this plant needs to grow and reproduce successfully. Multi-lang
Information not available in English. Help us expand this record!BehaviourDaily activity patterns, movement, territory use, foraging style, and seasonal behavioral changes. Multi-lang
It displays an aggressive phenological behavior. It is a plant that 'lives fast and dies young', reaching reproductive maturity in barely 3 or 4 years. To sustain that growth, it consumes water and depletes surface soil nutrients very rapidly. As the end of the rainy season approaches (or upon suffering water stress), the balsa massively defoliates its dense canopy of green leaves. The enormous and heavy white flowers (which sometimes accumulate so much water and nectar that they drip) open after sunset and remain receptive for just a single day before withering under the tropical midday heat.Toxicity / UsesToxic compounds present and their documented effects on humans or other organisms. Multi-lang
Information not available in English. Help us expand this record!Physical Measures
Length (cm)
500.0 - 3000.0 cm
Reproductive StructuresFlowers, fruits, and seeds — the reproductive organs and their seasonal appearance.
Flower Photos (Max 2)
No imageFruit Photos (Max 2)
No imageEvolutionary AdaptationsInherited traits and behaviors that improve the species' survival and reproduction in its specific environment. Multi-lang
Ultralight wood (Explosive growth): To win the race for sunlight in forest gaps, the balsa sacrifices density for speed. Its wood is composed of large cells (parenchyma) that are filled with water in the living tree to provide turgidity. When dried, these enormous cellular cavities hold only air, resulting in structurally robust wood with extremely low density (as low as 100-200 kg/m³), allowing it to grow up to 5 meters in a single year.
Anemochory and Photoblastic Seeds: The seeds are enveloped in a matrix of sand-colored, silky fluff (kapok). When the capsule opens in the dry season, the wind carries this fluff like snow for dozens of kilometers. The tiny seeds are 'positive photoblastic': they can remain dormant in the dark leaf litter for years, and only germinate when a tree fall suddenly allows the heat and direct sunlight to hit the forest floor.
Nocturnal floral architecture (Chiropterophily): The flowers open shortly before dusk. They are shaped like large, robust cups with thick petals that are not easily damaged. They produce a penetrating sweet scent and are filled with an immense volume of nectar (up to 30 ml per flower), a massive reward evolutionarily designed to attract and satiate the appetite of large nectarivorous bats and other nocturnal arboreal mammals that would not damage the resilient flower.
Main ThreatsDocumented pressures reducing the population: habitat loss, hunting, disease, climate change, and invasive species. Multi-lang
It is a species of Least Concern (LC) that paradoxically thrives on destructive human activity. Being a pioneer tree adapted to colonize landslides and clearings, the deforestation of jungles and the abandonment of pastures for agriculture regenerate its population massively, forming early successional forests composed purely of balsa (balsales).
Intensive commercial harvesting: Balsa wood is highly demanded by the aviation, marine, and recently, wind power industries (to manufacture the core of the huge wind turbine blades). Although large commercial plantations exist today, historically and in certain places, the clandestine logging of tall wild trees still occurs, drastically cutting short their natural life cycle.
Interesting FactsSurprising or notable facts that highlight what makes this species unique or ecologically important. Multi-lang
The literal name is 'Raft': The word 'balsa' means 'raft or flatboat' in Spanish. The Spanish conquistadors gave the tree this name after observing that Mesoamerican and South American indigenous peoples tied these extremely buoyant logs together with lianas to create stable river crafts or navigable rafts.
The Kon-Tiki Expedition: In 1947, Norwegian explorer Thor Heyerdahl built a replica of a primitive Inca raft using exclusively 9 giant balsa tree logs tied with hemp ropes. He set sail from Peru and successfully crossed almost 7,000 kilometers (4,300 miles) across the Pacific Ocean to Polynesia in 101 days, proving the invincible buoyancy of balsa despite becoming waterlogged, and demonstrating that ancient South American migration was possible.
It is the preferred wood for special effects in cinema. When an actor in an action movie breaks a chair or table over someone's head, these 'breakaway' props are traditionally constructed with painted hollow balsa wood. Being extremely fragile transversally and incredibly light, it shatters spectacularly upon impact without causing real injuries to the stuntmen.