The functions of:
1. Leaf spines: They help to reduce the loss of water by transpiration. They also help to protect the plant from the grazing animals, e.g. Cactus, mexican poppy.
2. Stem tendril: These stems provide support to the plant by coiling around some wall, tree etc. and helping the plant to climb, e.g. Passion flower, grapevine.
3. Phylloclade: These modified stems in desert plants carry out the function of preparation and storage of food. They fleshy stems also store water to be used in long dry periods, e.g. Opuntia.
4. Stilt roots: They fix the plant firmly to the soil in plants where the stem is weak and tall. They arise from the lower part of the stem
