Abstract
The nutational movements performed by the leaves of the “Sensitive plant”,Mimosa pudica L., result from periodical turgor variations taking place in the parenchymatous cells of specialized motor organs. The trajectories in the three kinds of leaf motor organs usually show irregular elliptical paths with a period ranging from 10 to 60 min. The morphological analogy of these turgor movements is discussed in relation to nutational movements observed in growing organs.