Closed leaves of Mimosa pudica, known as the sensitive or humble plant. So-called because when the leaves are touched during daylight hours, they fold together and the leaf stalks droop. They resume their former position after a short period if left undisturbed. Mimosa pudica is seen growing here among grass; it is fern-like in appearance with bipinnate leaves composed of numerous leaf- lets (here closed). Photographed in Peru.