Difference Between Adnate and Connate

The key difference between adnate and connate is that adnate organs are the dissimilar organs that are fused together while connate organs are similar types of organs that are fused together.

Adnation is the fusion of dissimilar organs together. In contrast, connation is the fusion of similar organs together. Connation can be seen commonly in flowers of angiosperms since most floral organs are often fused. Fused petals, fused stamens, fused sepals, fused carpels and fused anthers are characteristic features that help in differentiation of plants. Adnation is also a feature that is useful in the differentiation of plants. Some flowers have stamens fused with petals. In angiosperm flowers, adnate and connate flower parts can be seen frequently.

CONTENTS

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

What is Adnate?

Adnation is the fusion of dissimilar organs together. In other words, adnation is the union of parts or organs that are different. In flowers, adnation refers to the fusion of two or more whorls such as stamens and petals, etc.

In some plants, stamens of the flower are fused to the top of the pistil. The stamens of Primula vulgaris are adnate to the corolla.  Moreover, in some plants, the ovary is fused to a calyx tube.

What is Connate?

Connation is the fusion of similar type of organs. For example, petals of a flower can be fused together to form a tubular corolla. Therefore, connate structures are the same kind of organs that are united with each other. Connation is commonly seen in parts of flowers. In synsepalous, we can see sepals fused into a cup-like structure. Petals are fused with each other in sympetalous flowers.

In the morning glory Ipomoea, petals are connate. A syncarpous ovary has carpels that are fused together, so we can say that flower has connate carpels. Similarly, stamens are fused with each other in synandrous structure.

What are the Similarities Between Adnate and Connate?

• Both adnation and connation frequently occur in flowers.
• In both types, organs are fused with each other.

What is the Difference Between Adnate and Connate?

Different parts are fused in adnation while similar parts are fused in connation. In other words, adnation is the fusion of dissimilar organs, while connation is the fusion of similar type of organs. This is the key difference between adnate and connate. The fusion of stamens with petals is an example for adnation while the fusion of carpels together is an example for connation.

The following infographic summarizes the difference between adnate and connate in tabular form.

Summary – Adnate vs Connate

Adnation and connation are frequently seen in flowers. Adnation refers to the fusion of two or more whorls of a flower while connation refers to the fusion among a single whorl. In adnation, fusion takes place between dissimilar organs while in connation, similar types of organs fuse with each other. This is the key difference between adnate and connate.

Reference:

1. “Angiosperm – Reproductive Structures”. Encyclopedia Britannica, 2020, Available here.
2. “Connation”. En.Wikipedia.Org, 2020, Available here.

Image Courtesy:

1. “Primula vulgaris ENBLA06 2” By Enrico Blasutto – File:Primula_vulgaris_ENBLA06.jpg (CC BY-SA 3.0) via Commons Wikimedia
2. “Flower large stamen” (CC BY-SA 3.0) via Commons Wikimedia