Modified aerial stems meant for protection from grazing animals by becoming strong, stout, straight, woody and pointed structures known as thorns are seen in

In Bougainvillea and Citrus the aerial modified stems are modified axillary buds which become pointed, woody and provide protection and are called as thorns. In some grasses like Agropyron, strawberry, potato, ginger, turmeric, onion, garlic, lily, zaminkand, and Colocasia modified stems are totally underground and involved in vegetative propagation. Modified stems or branches are totally aerial, sensitive, wiry in cucumber, pumpkin, watermelon, grapevine and help in climbing are known as stem tendrils. In banana, pineapple and Chrysanthemum the sub-aerial stems are suckers which arise from basal and underground portion of stem, grow horizontally in the soil and then come out obliquely upward to develop as leafy shoots.