The petiole varies in length, being usually shorter than the lamina, but sometimes much longer.
In the larger veins of the leaf especially in the midrib, in the petiole, and in the young stem, a1 extremely frequent type of mechanical tissue is collenchyma.
The midrib, or petiole, has thus the appearance of a branch with FIG.
The petiole or leaf-stalk is the part which unites the limb or blade of the leaf to the stem.
In Lathyrus Aphaca and some other plants the true pinnate leaves are abortive, the petiole forms a tendril, and the stipules alone are developed, perform ing the office of leaves.