WordNet (r) 3.0 (2006):

action plant
    n 1: prostrate or semi-erect subshrub of tropical America, and
         Australia; heavily armed with recurved thorns and having
         sensitive soft grey-green leaflets that fold and droop at
         night or when touched or cooled [syn: sensitive plant,
         touch-me-not, shame plant, live-and-die, humble
         plant, action plant, Mimosa pudica]