To determine which floral formula represents the mustard plant, we need to analyze the floral formulas provided in the options and identify the one that corresponds to the characteristics of the mustard plant, which belongs to the Brassicaceae family.
### Step-by-Step Solution:
1. **Identify the Family of Mustard**:
- Mustard belongs to the Brassicaceae family. The typical floral formula for plants in this family is usually represented as:
- **P4 + 2 + 4** (4 petals, 6 stamens - 4 long and 2 short, and 2 fused carpels).
2. **Analyze Each Option**:
- **Option 1**: P3 + 3
- This indicates 3 petals and 3 sepals. The petals and sepals are fused. This formula does not match Brassicaceae and is more characteristic of the Liliaceae family.
- **Option 2**: Corolla 5, Sepals 5
- This indicates 5 petals and 5 sepals. This formula is typical of the Solanaceae family, which includes plants like potatoes, not mustard.
- **Option 3**: Corolla 5, Calyx 1 + 2 + 2, Androsium 9 + 1, Gynosium 1
- This formula suggests a complex structure with a vaxillary arrangement, which is not representative of the Brassicaceae family. This is more characteristic of the Fabaceae family.
- **Option 4**: Corolla 2 + 2, Calyx 4, Androsium 2 + 4, Gynosium 2 (fused)
- This formula indicates 2 petals and 2 sepals, with 6 stamens (4 long and 2 short) and 2 fused carpels. This structure aligns with the characteristics of the Brassicaceae family.
3. **Conclusion**:
- After analyzing all the options, the correct floral formula that represents the mustard plant (Brassicaceae) is **Option 4**.
### Final Answer:
**The floral formula that represents the mustard plant is Option 4: Corolla 2 + 2, Calyx 4, Androsium 2 + 4, Gynosium 2 (fused).**
