Which of the following is an example of actinomorphic flower?

The correct option is Datura.

Explanation:

Flowers can be classified based on their symmetry into three main categories:
1. Actinomorphic (Radial Symmetry): A flower that can be divided into two equal radial halves in any radial plane passing through the center. Examples include Datura, mustard, and chilli.
2. Zygomorphic (Bilateral Symmetry): A flower that can be divided into two similar halves only in one particular vertical plane. Examples include pea (Pisum), Cassia, and bean (including Sesbania).
3. Asymmetric (Irregular): A flower that cannot be divided into two similar halves by any vertical plane passing through the center (e.g., Canna).

Based on these definitions:
- Datura possesses radial symmetry, making it an example of an actinomorphic flower.
- Cassia, Pisum (pea), and Sesbania are members of the Fabaceae family, which typically have bilateral symmetry, meaning they are zygomorphic flowers.