Aquatic plants 1. Their roots are weakly formed or completely absent. 2. Their stems are soft and weak. 3. Submerged leaves are thin and highly fragmented and gaseous leaves are large and slightly fragmented. 4. The skin usually does not have cuticles. 5. There is no leaf spot , if there is, it is on the surface of the leaf. . The body has a lot of air chambers and these provide buoyancy. . The mesophyll tissue is not usually divided into palisade and spongy parenchyma cells. Desert plants 1. The roots are well-formed and branched. 2. The stems are hard and woody. 3. The leaves are thin or thick and succulent or thick and leathery. Sometimes the small needle is converted into a conch. 4. The skin has a thick layer of cuticle. 5. Leaf pores are located on the underside of the leaf in all cases. . The body does not have air chambers , instead it is seen to have water storage cells. In some cases mucilage cells are observed. . In most cases mesophyll tissue is divided into palisade and spongy parenchyma cells.