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

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 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.

Image:balsa.jpg|Three different sizes of balsa wood used for hobby purposes Image:balsa_airframe.jpg|Frame of a model airplane constructed entirely of balsa wood

External links

• Species description
• Germplasm Resources Information Network: Ochroma pyramidale
• Photo of foliage and flower
• Kon-Tiki museum website
• Balsa rafting in Ecuador

Malvaceae | Wood

Balsatræ | Balsabaum | Madera de balsa | Balsa (arbre) | バルサ | Ogorzałka (botanika) | Balsa | Balsa