In some plants the stems are modified to perform the function of storage of food, support, protection and vegetative propagation.
• For food storage : Rhizome (ginger), Tuber (potato), Bulb (onion), Corm (colocasia).
• For support : Stem tendrils of watermelon, grapvine, cucumber.
• For protection : Axillary buds of stem of citrus, Bougainvillea get modified into pointed thorns. They protect the plants from animals.
• For vegetative propagation : Underground stems of grass, strawberry, lateral branches of mint and jasmine.
• For assimilation of food : Flattened stem of opuntia contains chlorophyll and performs photosynthesis.
