Which tree yields the lightest wood in the world? And which tree is made of the heaviest?

Both the extremes present an interesting contrast and it’s fun to know. The lightest wood is that of the balsa tree, which grows principally in tropical South American countries like Ecuador and Costa Rica. The tree grows rapidly and decays quickly. There are different kinds of balsa wood. The lightest variety is so porous and the cell walls are so thin that about 75% of its volume is air. This is evident from the greatly enlarged photograph of its internal structure shown here. No wonder a cubic metre of such wood weighs only about 40 kilograms. Compare it with the black ironwood which has a density of 1,490 kilograms per cubic metre. Now, here’s something to wonder about: The black ironwood, which comes from the South African tree of the same name, has a specific gravity of 1.49. This means that unlike all other kinds of wood, it would sink in water. The balsa wood is an excellent construction material for model airplanes, though nowadays, it is being substituted by Styrofoam.