Leaf Venations
The arrangement of veins and veinlets on the lamina of a leaf is called venation. The venations are of two types- reticulate and parallel venation.
Reticulate venation – The venation in which the veins and veinlets are irregularly distributed throughout the lamina of the leaf, forming a network of lines, is called reticulate venation. Reticulate means ‘net-like’. For example: peepal, mango and guava have reticulate venation.
In the above picture of a mango leaf, you must would be observing several irregular lines on the lamina of the mango leaf. That’s why it is called reticulate type of venation.
Parallel Venation – The venation in which the veins run parallel to each other are said to have parallel venation. For example: wheat, banana and grass.
This is a close picture of a banana leaf. You can see many straight lines on the leaf lamina. So you can say that parallel venation is just opposite of reticulate venation.