Balsa

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

{{Taxobox | color = lightgreen | name = Balsa | regnum = Plantae | divisio = Magnoliophyta | classis = Magnoliopsida | ordo = Malvales | familia = Malvaceae (Bombacaceae) | genus = Ochroma | species = O. lagopus | binomial = Ochroma lagopus | binomial_authority = Sw. }}

Balsa (Ochroma lagopus, synonym O. pyramidale) 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 ordinary wood). This makes it a very popular material for model making 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 wooden light aeroplanes, typically sandwiched between two pieces of thin plywood.

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