Netted venation is a form of leaf venation composed of veins arranged in a net-like pattern. The veins branch from the major midribs and split into smaller stands of veinlets, which subsequently unite to form a composite network. Netted venation occurs in the leaves of almost all dicotyledonous angiosperms.
Examples of plants with netted venation include maple, oak, hibiscus, redgram and rose. Net venation is also known as reticulate venation, and is further classified into pinnate and palmate venation. Pinnate venation is as well-known as unicostate venation, while palmate venation is also known as multicostate venation.
In pinnate venation, the veins extend crossing the midrib to the circumference, as seen in apple, mango, peepul, guava, cherry and peach plants. Pinnate venation typically shows one vein more outstandingly than the others, and consists of veins that run from the base of the leaf blade to its tip in a central longitudinal arrangement. The outstanding vein is the midrib of the leaf. It forms veins that proceed towards the edge of the leaf.
In palmate venation, the main veins extend away from the petiole like blades of a fan close to the end of the leaf blades. This is seen in grapes, maple and other plants made up of two seed leaves. Palmate venation has one or more prominent veins that emanate from the foot of the leaf blade. When the veins come together towards the margin, the venation is referred to as multicostate convergent, as seen in zizyphus. When the veins diverge, they are termed multicostate divergent, as in cotton.