Modifications of leaf

Leaves with different functions or modification of leaves:

They can perform special functions other than photosynthesis, Prominent examples are:

1. Leaf tendrils: Tendrils are thread-like green structures, which are sensitive to touch and are capable of coiling around the support. They can be differentiated from stem tendrils by absence of scaly leaves over them and being unbranched. Following are the examples of leaf tendrils for e.g., pisum, sativum.

 

2. Leaf spines: In plants like Barberry, Opuntia, Aloe and Argemone leaves are modified into spines. Spines protect the plant from grazing animals and also reduce the area for transpiration.

3. Food storage: Food is stored in the leaves of Allium cepa (onion). The leaves may also become fleshy or juicy (succulent) due to storage of water, mucilage and food material e.g. Aloe.

4. Leaf pitcher: In Nepenthes or Pitcher plant pitchers are held vertically by a tendril like, slender coiled stalk, petiole. The lid of pitcher represents the modified leaf apex. Leaf lamina is modified into pitcher.

5. Leaf bladder: In insectivorous plants like Utricularia (bladder wort), leaves are modified to form bladder. Such plants have mechanism to catch insects and fee on them. 

6. Phyllode: In case of Australian acacia (Acacia auriculiformis) the normal leaf is bipinnate compound. The leaflets disappear, petiole get flattened and green in colour to perform the function of photosynthesis.

7. Leaf hooks: In Bignonia unguis cati three terminal leaflets of compound leaf are modified into claw like hooks which help the plant in climbing.