The key difference between pulvinus and petiole is that pulvinus is the small swelling present at the base of a leaf, facilitating the movement of the leaf, while petiole is the leaf stalk that connects the leaf blade to stem.
Pulvinus and petiole are two important structures found in plants. Both structures are related to plant leaves. Pulvinus is a small swelling situated at the point where the petiole joins the leaf to stem. Therefore, pulvinus is seen at the base of the petiole. It facilitates growth independent leaf movements. Petiole is the leaf stalk which connects the leaf into the stem.
