Leaves

When looking at a flowering plant, perhaps the most obvious features are the leaves. The green colour gives the key to their vital role in carrying out photosynthesis. Look more closely at a whole leaf on different plants and variations in shape, size and arrangement on the stem become evident. While there is considerable diversity, fundamentally the shape and position of leaves are geared to maximise photosynthesis for the plant. Internally, the arrangement of cells and tissues repeats the story of increasing the efficiency of photosynthesis: there are structures that enable gas exchange to take place and structures that bring water to the cells containing chloroplasts with the green pigment chlorophyll, where photosynthesis takes place.

Images presented in this section introduce the basic features of whole leaves, from a range of plants, and show some of their variations. Then a detailed look at internal structures of the leaf gets closer to the site of photosynthesis in the chloroplasts. Two more sub-sections illustrate some of the adaptations shown by leaves to different habitats (dry, wet and salty) and other interesting and exciting modifications that help plants survive in their particular environment.


Features of whole leaves and their arrangement on the plant
Internal structures and their functions
Some adaptations to habitats - xerophytes, hydrophytes and halophytes
More adaptations and how they help the plant - carnivorous plants, defences and sunscreens