The large volume-to-surface ratio of the resulting thin-walled, empty cells gives the dried wood a large strength-to-weight ratio because the cells are mostly air. For commercial production, the wood is kiln-dried for about two weeks, leaving the cells hollow and empty. It also makes the wood of the living tree not much lighter than water and barely able to float. The wood of the living tree has large cells that are filled with water. Balsa is the softest wood ever measured using the Janka hardness test (22 to 167 lbf). The density of dry balsa wood ranges from 40 to 340 kg/m 3, with a typical density around 160 kg/m 3. Three different sizes of balsa wood stockīalsa lumber is very soft and light, with a coarse, open grain. The trees are harvested after six to 10 years of growth. In recent years, about 60% of the balsa has been plantation-grown in densely packed patches of around 1000 trees per hectare (compared to about two to three per hectare in nature). It is evergreen or dry-season deciduous, with large 30 to 40 centimetres (12 to 16 in), weakly palmately lobed leaves.īeing a deciduous angiosperm, balsa is classified as a hardwood despite the wood itself being very soft it is the softest commercial hardwood.Įcuador supplies 95% or more of commercial balsa. The main pollinators were once thought to be bats, but recent evidence suggests that two nocturnal arboreal mammals, the kinkajou and the olingo, may be the primary pollinators.

However, most pollination occurs at night. Daytime pollinators include capuchin monkeys. Each may contain a pool of nectar up to 2.5 centimetres (0.98 in) deep. The large flowers open in the late afternoon and remain open overnight. įlowers are produced from the third year onwards, typically at the end of the rainy season when few other trees are in flower. Trees generally do not live beyond 30 to 40 years. The speed of growth accounts for the lightness of the wood, which has a lower density than cork. It grows extremely rapidly, up to 27 metres (89 ft) in 10–15 years.

It is a pioneer plant, which establishes itself in clearings in forests, either man-made or where trees have fallen, or in abandoned agricultural fields. Balsa on Bota Hill, Limbe Botanical Garden, CameroonĪ member of the mallow family, Ochroma pyramidale is native from southern Mexico to southern Brazil, but can now be found in many other countries (Papua New Guinea, Indonesia, Thailand, Solomon Islands).

Synonyms for achroma