Question

Explain leaf modification with examples.

Answer 1

In many plants, leaves get modified to perform some special functions other than the normal ones, such as photosynthesis and transpiration.

Sometimes these modifications are in response to certain environmental conditions.

1. Storage Leaves:

Some plants of xerophytic habitats and members of the family Crassulaceae generally have highly thickened and succulent leaves with water storage tissue. These leaves have large parenchymatous cells with big central vacuole filled with hydrophilic colloids. This kind of adaptation helps plants to conserve a very limited supply of water and resist desiccation (drying up).

2. Leaf Tendrils:

In weak-stemmed plants, a leaf or a part of the leaf gets modified into green thread ­like structures called tendrils which help in climbing around the support.

3. Leaf-spines:

Leaves of certain plants become wholly or partially modified for defensive purposes into sharp, pointed structures known as spines. The leaf-apex in date-palm, dagger plant (Yucca), etc., is so modified.

4. Scale-leaves:

Typically these are thin, dry, stalkless, membranous structures, usually brownish in colour or sometimes colourless. Their function is to protect the axillary bud that they bear in their axil. Scale-leaves are common in parasites, saprophytes, underground stems, etc.