The thick outer coating, or cuticle, on evergreen needles helps to reduce water loss through transpiration. By limiting the amount of water that can escape from the needle's surface, the cuticle helps the plant conserve moisture and maintain hydration levels necessary for photosynthesis. This allows the plant to continue photosynthesizing even in dry or arid conditions where water is limited. Additionally, the cuticle also helps protect the leaf from damage caused by environmental factors such as wind, temperature extremes, and pathogens, ensuring that the plant can continue to efficiently carry out photosynthesis.
