Light micrograph of the surface of a leaf of the sensitive plant, Mimosa pudica, showing the interlocking, jigsaw-like network of epidermal cells. The tiny, leaf-shaped structures visible on the leaf surface are stomata (pores), which provide the plant with a means of gaseous exchange between the atmosphere & the internal tissues. The pores are held open during the day & are closed at night to conserve water. M. pudica is known as the sensitive plant because it reacts to being touched; the leaves fold together rapidly and the leaf stalks droop. The plant quickly recovers its former shape if left undisturbed. Magnification: x400 at 35mm size.