Aeschynomene elaphroxylon, also known as an ambatch, pith tree or balsa wood tree, is a common large shrub to small tree of the genus Aeschynomene in the family Fabaceae. It can grow up to 9 m high, with spiny stems, and pairs of substantial thorns under the base of leaves.A. elaphroxylon is indigenous to parts of tropical Africa. It typically grows by water and in waterlogged soils.The seeds of A. elaphroxylon have been known to stay viable after being buried for a few years in the waterlogged banks ...