By learning how to recognize parallel, pinnate, palmate, and other vein patterns you gain access to powerful tools for identifying plants even outside flowering seasons. Many leaves have a midrib, which travels the length along the center of the leaf The leaf veins are small channels or capillaries that transport water and minerals to and from the leaf of a plant
Vein | plant structure | Britannica
They are vascular tissues composed of xylem and phloem cells embedded mainly in the parenchyma and sometimes sclerenchyma cells
The outer layer of veins is made of bundle sheath cells.
In the classical concept of a microphyll, the leaf vein emerges from the protostele without leaving a leaf gap Leaf gaps are small areas above the node of some leaves where there is no vascular tissue, as it has all been diverted to the leaf Megaphylls, in contrast, have multiple veins within the leaf and leaf gaps above them in the stem. Leaves are essential organs of plants that play a crucial role in photosynthesis, transpiration, and gas exchange
One of the most important features of leaves is their venation—the pattern of veins running through the leaf blade Venation not only provides support and structure to the leaf but also aids in the transport of water, nutrients, and food throughout the plant Most leaves have a midrib, which travels the length of the leaf and branches to each side to produce veins of vascular tissue The edge of the leaf is called the margin
Figure 30.21 shows the structure of a typical eudicot leaf
Figure 30.21 deceptively simple in appearance, a leaf is a highly efficient structure. In a special type of sessile leaves called perfoliate leaves, the stem passes through the center of the blade (figure 3 4 1 4)
