Which of the following statements about the Fabaceae family is incorrect ?

Options

A. Ornamental plants such as lupin, petunia and sweet pea are included in this group
B. They have diadelphous stamens and their anthers are dithecous
C. Their sepals may show valvate or imbricate aestivation
D. They have a monocarpellary gynoecium with a superior ovary

Answer

To determine which statement about the Fabaceae family is incorrect, we will analyze each statement provided in the question.

### Step-by-Step Solution:

1. **Identify the Family**: The Fabaceae family, also known as the legume, pea, or bean family, includes a variety of plants. It was previously classified under the sub-family Papilionoideae.

2. **Examine the Statements**:
- **Statement 1**: "There are ornamental plants such as Lupine, Petunia, and Sweet Pea included in this group."
- **Analysis**: Lupine and Sweet Pea are indeed part of the Fabaceae family. However, Petunia belongs to the Solanaceae family (the nightshade family) and is not part of Fabaceae. Therefore, this statement is incorrect.

- **Statement 2**: "It has got a Diadelphous stamens and their anthers are Diathecal."
- **Analysis**: This statement is correct. The Fabaceae family typically has 10 stamens, with 9 fused together and 1 free, which is known as diadelphous.

- **Statement 3**: "Valvate or imbricate estivation is represented by one standard petal, two lateral petals which are free from each other, and two small petals called the keel."
- **Analysis**: This statement is also correct. The floral structure of Fabaceae often includes this arrangement of petals.

- **Statement 4**: "All members of the family Fabaceae show valvular or papillonaceous estivation."
- **Analysis**: This statement is correct as well. The members of this family typically exhibit papillonaceous (butterfly-like) estivation.

- **Statement 5**: "They have a monocarpillary gynoecium with a superior ovary."
- **Analysis**: This statement is correct. Fabaceae plants generally have a single carpel and a superior ovary.

3. **Conclusion**: The only incorrect statement is the first one, which incorrectly includes Petunia as a member of the Fabaceae family.

### Final Answer:
The incorrect statement about the Fabaceae family is: "There are ornamental plants such as Lupine, Petunia, and Sweet Pea included in this group."