If a flower exhibits bilateral symmetry only i.e., symmetry of one plane, it is called

Options

A. actinomorphic
B. zygomorphic
C. asymmetrical
D. dimorphic

Answer

To answer the question, "If a flower exhibits bilateral symmetry only, i.e., symmetry of one plane, it is called," we need to analyze the different types of floral symmetry.

### Step-by-Step Solution:

1. **Understanding Floral Symmetry**: Floral symmetry refers to the arrangement of floral parts (like petals) in a way that allows the flower to be divided into identical parts. There are different types of symmetry: actinomorphic, zygomorphic, asymmetrical, and dimorphic.

2. **Actinomorphic Flowers**: These flowers have radial symmetry, meaning they can be divided into two or more identical halves through multiple planes. An example is the buttercup. Since the question specifies bilateral symmetry (one plane), actinomorphic is not the correct answer.

3. **Zygomorphic Flowers**: Zygomorphic flowers exhibit bilateral symmetry, meaning they can be divided into two identical halves through only one plane. An example is the viola. This matches the definition provided in the question.

4. **Asymmetrical Flowers**: These flowers lack any symmetry, meaning they cannot be divided into identical halves. An example is the Kana plant. This does not fit the requirement of bilateral symmetry.

5. **Dimorphic Flowers**: This term refers to flowers that have male and female forms that differ morphologically. It does not relate to symmetry, so it is not the correct answer.

6. **Conclusion**: Given the definitions and examples, the flower that exhibits bilateral symmetry (symmetry of one plane) is called **zygomorphic**.

### Final Answer:
The correct answer is **zygomorphic**.