Venation is the phenomenon of arrangement of veins in the lamina of the leaf surface. It is of three types, reticulate, parallel and furcate venation. In reticulate venation, veins form the network like structure. For example, leaves of dicot plants. In parallel venation, veins arise from the mid rib and run parallel. For example, leaves of monocot plants. In furcate venation, veins form dichotomous branching. For example, leaves of fern.