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 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.

Despite its softness, balsa is classified as a hardwood.

External links

• Species description (http://ctfs.si.edu/webatlas/english/ochrpy.html)
• Photo of foliage and flower (http://www.tfts.org/ochroma_lagopus.htm)
• Kon-Tiki museum website (http://www.museumsnett.no/kon-tiki/)
• ITIS 21602 (http://www.itis.usda.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=21602)

See also Balsa (email client)