The part of leaf by which it is attached to the stem is called petiole. The broad, green part of the leaf is called lamina .
These lines on the leaf are called veins. A prominent line in the middle of then leaf, This is called
the midrib. The design made by veins in a leaf is called the leaf venation. If this design is net-like on both sides of midrib, the venation is reticulate. In the leaves of grass you might have seen that the veins are parallel to one another. This is parallel venation .Observe the venation in as many leaves as you can without removing them from the plant