Difference Between Pinnatifid and Pinnatisect

The key difference between pinnatifid and pinnatisect is that pinnatifid leaves have lobes with incisions that extend less than half-way toward the midrib while pinnatisect leaves have lobes with incisions that extend almost up to the midrib.

Leaves are the primary sites that carry out photosynthesis in plants. They capture sunlight and produce carbohydrates for the entire plant. A leaf has a leaf blade called leaf lamina. Leaf shape and size differ among different plants. Therefore, leaf shape is a good feature that botanists use to differentiate plants in taxonomy. There are many different leaf shapes. Pinnate is a type of leaf that has leaf-lets arranged in both lateral sides of the main vein. Pinnatifid and pinnatisect are two types of leaves that are incompletely divided. Both do not have separate leaflets. These two types differ from each other primarily by the leaf incisions or cuts in the lamina that go up to the midrib. In pinnatifid leaves, incisions extend less than half-way toward the midrib. In pinnatisect leaves, incisions extend almost or up to the midrib.

CONTENTS

1. Overview and Key Difference
2. What is Pinnatifid
3. What is Pinnatisect
4. Similarities Between Pinnatifid and Pinnatisect
5. Side by Side Comparison – Pinnatifid vs Pinnatisect in Tabular Form
6. Summary

What is Pinnatifid?

Pinnatifid is a type of pinnate leaf based on the depth of the divisions. Pinnatifid leaves have lobes with incisions extending less than half-way towards the midrib. Therefore, the leaf lobes are not discrete. They remain connected to each other. Hence, pinnatifid leaves do not have separate leaflets. However, they do have leaflets on both sides of the midrib.

Elaphoglossum is a fern which has pinnatifid leaves. Polybotrya is another genus of ferns that has a pinnatifid frond apex. Enterosora also has simple to pinnatifid fronds.

What is Pinnatisect?

Pinnatisect is another type of pinnate leaves that have incomplete divisions. Pinnatisect leaves have lobes with incisions that extend almost, or up to midrib. Therefore, the lamina of pinnatisect leaves cut down almost to the midrib. But the bases of the pinnae are not contracted to form discrete leaflets.

Many ferns have pinnatisect or pinnatifid fronds. Alansmia is an epiphytic fern that has pinnatiscect fronds. Polypodium lindenianum is another fern that has pinnatisect fronds.

What are the Similarities Between Pinnatifid and Pinnatisect?

• Pinnatifid and pinnatisect are two types of pinnate leaves.
• Both have lobes with incisions running toward the midrib.
• Ferns have both pinnatifid and pinnatisect leaves.
• Both pinnatifid and pinnatisect fronds are incompletely divided, so both pinnatifid and pinnatisect leaves have no separate leaflets.

What is the Difference Between Pinnatifid and Pinnatisect?

Pinnatifid and pinnatisect are two types of incompletely divided pinnate type leaves. However, both types do not have separate leaflets. Pinnatifid leaves have lobes with incisions extending less than half-way towards the midrib. Pinnatisect leaves have lobes with incisions extending almost or up to the midrib. So, this is the key difference between pinnatifid and pinnatisect.

Below infographic summarizes the difference between pinnatifid and pinnatisect.

Summary – Pinnatifid vs Pinnatisect

A pinnate leaf is a compound leaf that has leaflets on each side of the midrib or common axis. Pinnatifid and pinnatisect leaves are two types of leaves based on the depth of divisions or incisions. Pinnatifid leaves have lobes with incisions going less than half-way toward the midrib. Pinnatisect leaves have lobes with incisions extending almost or up to midrib. Thus, this is the key difference between pinnatifid and pinnatisect. However, both pinnatifid and pinnatisect leaves do not have separate leaflets. Their divisions are incomplete.

Reference:

1. “Pinnation”. En.Wikipedia.Org, 2020, Available here.
2. “Plantnet – Floraonline – Glossary”. Plantnet.Rbgsyd.Nsw.Gov.Au, 2020, Available here.

Image Courtesy:

1. “Elaphoglossum peltatum Costa Rica” By Gabriele Kothe-Heinrich – Own work (CC BY-SA 3.0) via Commons Wikimedia

2. “Silver-fern” By Tatania Gerus – (CC BY 2.0) via Commons Wikimedia