Leaves - Adaptations

Adaptations

In the course of evolution, leaves have adapted to different environments in the following ways:

• A certain surface structure avoids moistening by rain and contamination (See Lotus effect).
• Sliced leaves reduce wind resistance.
• Hairs on the leaf surface trap humidity in dry climates and create a boundary layer reducing water loss.
• Waxy leaf surfaces reduce water loss.
• Large surface area provides large area for sunlight and shade for plant to minimize heating and reduce water loss.
• In harmful levels of sunlight, specialised leaves, opaque or partly buried, admit light through translucent windows for photosynthesis at inner leaf surfaces (e.g. Fenestraria).
• Succulent leaves store water and organic acids for use in CAM photosynthesis.
• Aromatic oils, poisons or pheromones produced by leaf borne glands deter herbivores (e.g. eucalypts).
• Inclusions of crystalline minerals deter herbivores (e.g. silica phytoliths in grasses, raphides in Araceae).
• Petals attracts pollinators.
• Spines protect the plants (e.g. cacti).
• Special leaves on carnivorous plants are adapted to trapping food, mainly invertebrate prey, though some species trap small vertebrates as well (see carnivorous plants).
• Bulbs store food and water (e.g. onions).
• Tendrils allow the plant to climb (e.g. peas).
• Bracts and pseudanthia (false flowers) replace normal flower structures when the true flowers are greatly reduced (e.g. Spurges).