Leaf Venation Notes

Leaf venation is the term used to describe the arrangement of veins in a leaf lamina.

Leaves are the most important vegetative structure, as they perform photosynthesis. They develop from shoot apical meristems and are borne on the stem at nodes. A leaf consists of three main parts: leaf base, lamina and petiole.

Lamina, commonly referred to as a leaf blade, is composed of veins and veinlets. The most prominent vein in the middle is referred to as the midrib. These veins provide rigidity to the leaf lamina and are also responsible for the transport of food, minerals, and water.

Leaf Venation

Leaf venation refers to the pattern of veins and veinlets in the leaf lamina. There are two main types of leaf venation:

  1. Reticulate Venation - In this type of venation, veinlets form a network which is generally found in dicotyledonous plants.

  2. Parallel Venation: In this type of venation, veins run parallel to each other and is typically found in monocotyledonous plants.

Some leaves show dichotomous venation, e.g. in Gingko biloba. The veins branch from each other like tree branches.

Veins contain vascular bundles, consisting of xylem and phloem cells, which respectively transport water and minerals to the leaf lamina and sugar to the other parts of the plant.

NEET NCERT Solutions (Biology)