Balsa trees grow in the South American countries of Brazil and Bolivia. They can also sometimes be found in Mexico.
Balsa trees... or your local hobby shop.
from my balls
Latin America
Balsa trees are native to southern Brazil, Bolivia and north to southern Mexico. They can be grown in Hawaii and Guam and are related to the cotton plant. Ecuador supplies 95% of the commercial balsa. So to get back to your question, unless you live where the balsa tree can be grown, it is NOT locally grown.
Central America.
The balsa wood tree, scientifically named ochroma lagopus, is a relatively fast growing plant found primarily in Central and South America. Balsa wood trees grow best under the conditions found in rainforests, ideally in mountainous terrain between rivers. The country of Ecuador is perhaps the largest exporter of balsa wood, although many local farmers consider the plant to be little more than a weed.* http://www.wisegeek.com/what-is-balsa-wood.htmAnother site with good information:* http://www.mat.uc.pt/~pedro/ncientificos/artigos/techbal.html
balsa tree trunks
They grow on a plant in Africa. They grow in bunches on trees in places like South America.
Fir, Balsa, Douglass
Balsa wood is the wood of the balsa tree, Latin name Ochroma pyramidale.
Balsa wood is native to southern Brazil and Bolivia and can grow as far north as southern Mexico. Equador supplies 95% of the commercial balsa. It can be grown in Hawaii and Guam, and is in the cotton family of plants. Their flowers are pollinated by the capuchin monkeys and other nocturnal mammals, but not bats. It is a "pioneer" plant - it moves in when a space has been cleared whether it is a man-made cutting or fallen trees or fire devastation.