Balsa

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For the e-mail client, see Balsa (e-mail client).

iBalsa

Scientific classification

Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Malvales
Family:	Malvaceae (Bombacaceae)
Genus:	Ochroma Sw.
Species:	O. pyramidale

Binomial name

Ochroma pyramidale
(Cav. ex Lam.) Urb.

Balsa (Ochroma pyramidale, synonym O. lagopus) is a large, fast-growing tree to 30 m tall, native from tropical South America north to southern Mexico. It is evergreen, or dry-season deciduous if the dry season is long, with large (30–50 cm) weakly palmately lobed leaves. The name balsa derives from Spanish for a raft.

The timber is very soft and light with a coarse open grain. The density of balsa wood ranges from 100–200 kg/m³, with a typical density of about 140 kg/m³ (about one third the density of other kinds of hard wood). This makes it a very popular material for model building and buoyancy materials (lifebelts, etc.), and was famously used by Thor Heyerdahl in his raft Kon-Tiki. It is also used to make very light, stiff structures in model bridge tests, light wooden aeroplanes, table tennis blades, typically sandwiched between two pieces of thin plywood, and also is used in the Chevrolet Corvette bodies tub.

Despite being very soft, balsa is classified as a hardwood, the softest commercial hardwood.