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.
CONTENTS
1. Overview and Key Difference
2. What is Pulvinus
3. What is Petiole
4. Similarities Between Pulvinus and Petiole
5. Side by Side Comparison – Pulvinus vs Petiole in Tabular Form
6. Summary
What is Pulvinus?
Pulvinus is the swelling at the base of a leaf. It is the organ facilitating the movement of the leaf. It is located at the point where the petiole joins the leaf to stem. Pulvini are localized and specialized areas in stems or leaves composed of a group of thin-walled parenchyma cells.
Figure 01: Pulvinus
The leaf movements are facilitated by the pulvinus due to the changes in turgor pressure of motor cells. In the sensitive plants, like Momosa pudica, the pulvinus is responsible for the folding of leaves upon touch or injury. Moreover, in plants such as Albizzia and Samanea, leaf movements are controlled by the different turgor pressure changes in pulvinal motor cells.
What is Petiole?
Leaves are the sites that produce carbohydrates by the process of photosynthesis. The petiole is the stalk that connects a leaf to the stem. In other words, the petiole is the leaf stalk. Petiole holds the leaf blade. Petioles are mainly greenish in colour and also able to produce food via photosynthesis. Furthermore, petioles are the structures that are responsible for the leaf falls in deciduous plants during the fall season. The length of the petiole can vary in different plants. They can be long, short or completely absent. If petioles are absent or if leaves join the stem without petioles, we call those leaves sessile leaves.
Figure 02: Petiole (1)
Petioles provide the path to transport food, water, etc. When leaves produce food, they are transported to the other parts of the plant through the petiole. Furthermore, the ingredients necessary to carry out photosynthesis by leaves are supplied via the petioles. Moreover, petioles play an important role in directing leaves to the sunlight for capturing more sunlight for photosynthesis.
What are the Similarities Between Pulvinus and Petiole?
- Both pulvinus and petiole are two structures related to leaves.
- Pulvinus is present at the base of the petiole.
- Some plants do not have pulvini and petioles.
- Both pulvinus and petiole are green in colour.
What is the Difference Between Pulvinus and Petiole?
Pulvinus is the swollen base of the leaf. In contrast, the petiole is the leaf stalk. So, this is the key difference between pulvinus and petiole. Moreover, pulvinus facilitates growth independent movements of the leaf while petiole attaches the leaf to stem.
The following table summarizes the difference between pulvinus and petiole.
Summary – Pulvinus vs Petiole
Pulvinus is the swollen leaf base while petiole is the leaf stalk. Both structures are related to leaves of plants. Pulvinus is mostly present at the base of petiole where the leaf joints to the stem. It facilitates growth independent movements of leaves. Petiole attaches the leaf to stem. It also aids the transportation of nutrients from the leaf to other parts and transport water and minerals to leaves. This is the summary of the difference between pulvinus and petiole.
Reference:
1. “Pulvinus”. En.Wikipedia.Org, 2020, Available here.
2. “Petiole: Definition & Function.” Study.Com, 2020, Available here.
Image Courtesy:
1. “Starr 070306-5195 Angiopteris evecta” By Forest & Kim Starr (CC BY 3.0) via Commons Wikimedia
2. “Petiole (PSF)” By Pearson Scott Foresman – Archives of Pearson Scott Foresman, donated to the Wikimedia FoundationThis file has been extracted from another file: PSF P-680002.png (Public Domain) via Commons Wikimedia