Mimosa pigra, commonly known as the giant sensitive tree (pigra = lazy, slow), is a species of plant of the genus Mimosa, in the family Fabaceae. The genus Mimosa (Mimosaceae) contains 400–450 species, most of which are native to South America. M. pigra is a woody shrub native to tropical America but which has now become widespread throughout the tropics. It has been listed as one of the world's 100 worst invasive species and forms dense, thorny, impenetrable thickets, particularly in wet areas.