Aquatic plants are those plants that grow in water.
Lotus is an emerged aquatic plant. It has plate-like broad leaves. Its roots are fixed into the soil and stems are several inches long and emerged out of water.
Desert plants:
Desert plants are terrestrial plants that grow on very hot and dry habitat and store water in their stem tissues to reduce transpiration.
Cactus is a desert plant. it have reduced and spine-like leaves, spongy stem and well-developed and widespread roots.
Final answer:Lotus: aquatic plants, Cactus: desert plants.