"Pudica" is the Latin word for "shy" or "bashful," which is an apt description of the sensitive "Touch-Me-Not." Native to South and Central America, this shade-lover often grows as a weed under trees and shrubs. It is popular among collectors as a specimen plant worldwide, because of its unique sensitivity to touch.
The foliage retracts when touched to prevent consumption by herbivores, and it also exhibits nyctinastic movement, meaning its circadian rhythms affect its leafs to close at night, and re-open during the day.
This trait is present in many other members of the legume family as well.
You can buy seeds for this plant and grow it yourself: