Simarouba is a genus of trees and shrubs in the Simaroubaceae family, native to the neotropics. It has been grouped in the subtribe Simaroubina along with the Simaba and Quassia genera. They have compound leaves, with between 1 and 12 pairs of alternate pinnate leaflets. Their flowers are unisexual, relatively small (around 1 cm long) and arranged in large panicles. The individual flowers have between 4 and 6 sepals and petals and between 8 and 12 stamens.