Mimosa pigra 060122-5358

Mimosa pigra (Giant Sensitive Tree) (pigra = lazy,slow), is an invasive species of the genus Mimosa, in the family Fabaceae. It is native to the Neotropics, but has been listed as one of the world's 100 worst invasive species, and has been documented in: Australia, Cambodia, Dominican Republic, Ghana, Guinea, Indonesia, Kenya, Malaysia, Papua New Guinea, South Africa, Sri Lanka, Swaziland, Tanzania, Thailand, Uganda, Zambia, United States, and Viet Nam (Vietnam). It forms dense, thorny impenetrable thickets particularly in wet areas.

In the late 1960s, small infestations of Mimosa pigra were identified along the banks of the Adelaide River in the Northern Territory, Australia. Action was taken by the N.T. Agriculture Branch to exterminate it by spraying with Tordon, which was promising to achieve eradication until the N.T government discontinued the work allowing the weed to spread widely and become the N.T's and possibly Australia's worst weed problem.^{[citation needed]}

Mimosa is a genus of about 400 species of herbs and shrubs, in the subfamily Mimosoideae of the legume family Fabaceae. The generic name is derived from the Greek word μιμος (mimos), meaning "mimic."

There are two species in the genus that are notable^{[citation needed]}. One is Mimosa pudica, because of the way it folds its leaves when touched or exposed to heat. It is native to southern Central and South America but is widely cultivated elsewhere for its curiosity value, both as a houseplant in temperate areas, and outdoors in the tropics. Outdoor cultivation has led to weedy invasion in some areas, notably Hawaii. The other is Mimosa tenuiflora, which is best known for its use in shamanic ayahuasca brews due to the psychedelic drug DMT found in its root bark.