Leaf Veins

1. Transportation

Leaves need water for photosynthesis. The primary function of leaf veins is transporting water, minerals, and food throughout the leaf.

The xylem moves fluids from the root upwards, entering the leaf through the midrib and then branching off with the help of venules. On the other hand, the phloem transports food produced in the leaf to all other parts of the plant.

2. Providing Structural Support

Plant veins also act as a skeleton, supporting the structure of the plant. Veins form delicate patterns branching into smaller and smaller veins that form the framework of the leaf.

Leaf veins are of two main types based on their pattern of arrangement:

1. Parallel Veins

They commonly run parallel to each other throughout the length of the leaf. Less typically, parallel veins also run laterally from the leaf’s midrib to the leaf edge.

Parallel veins are found in monocot plants such as rice, corn, corn, lilies, and grass. Although not parallel in its strict sense, none of the veins cross each other. They seem to fuse at the top or bottom of the leaf blade.

2. Netted Veins

They have their veins in a branching pattern. The veins interconnect, giving a netted look to the leaf blade.

Netted veins are found in dicot plants. Flowering plants, fruit and deciduous trees, vegetables (except corn), wildflowers, and many shrubs are plants with netted veins.

Netted veins can be of 2 types –

a) Pinnately Netted – Veins of elms and oaks where several smaller veins branch out from a dominant midrib.

b) Palmately Netted – Veins of maples and redbud where several dominant veins branch out from the petiole.

Apart from the two dominant types, a few plants, such as leaves of Ginkgo biloba, have a spreading vein pattern called dichotomous venation.