Ochroma

Ochroma is a genus of flowering trees in the Malvaceae family, native to tropical regions of the Americas. The best known species is Ochroma pyramidale, commonly called the balsa tree, which is especially valued for its exceptionally light wood.

These are fast-growing, canopy-emergent trees that can reach 15 to 30 meters in height. They have large palmately lobed leaves and small, pale pink to white flowers. The fruit is a dry capsule that releases numerous wind-dispersed seeds.

Ochroma is native to tropical lowland forests from southern Mexico to Bolivia, including the Amazon basin. They prefer moist, high-rainfall environments and can colonize disturbed sites, contributing quickly to forest regeneration in some regions.

The wood of Ochroma is extremely light for a timber species, with a density around 0.1 g/cm3. It is easy to cut, plane, and glue, making it popular for model airplanes, crafts, and lightweight cores in composite panels. Its softness and low stiffness limit load-bearing applications, and it is prone to moisture-related damage if not protected.

Commercial cultivation occurs in tropical regions where rapid growth is possible. Plantations often harvest trees within five to eight years, reflecting the genus’s fast rotation and high growth rates. Because of these properties, balsa has been extensively managed and traded worldwide.

There are several species within the genus, but Ochroma pyramidale remains the principal source of timber used for lightweight, easily worked wood.