plant-a-day:

Sensitive Plant

Mimosa pudica

"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 circadian rhythms affect the leaves to close at night, and re-open during the day.