The incorrect statement among the following is:

Options

A. Phyllotaxy is whorled in Alstonia.
B. Ovaries are half superior in rose, peach and plum.
C. Ovules are borne on central axis in axile placentation.
D. Placenta is the site of attachment of gynoecium in flower.

Answer

To solve the question of identifying the incorrect statement among the provided options, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Understanding Phyllotaxy**:
- The first statement mentions "phyllotaxy is world in Elstonia."
- Phyllotaxy refers to the arrangement of leaves on a stem.
- World phyllotaxy occurs when more than two leaves arise from a single node, forming a whorl.
- In Elstonia, this type of phyllotaxy is indeed observed.
- **Conclusion**: This statement is correct.

2. **Position of Ovaries in Flowers**:
- The second statement claims "ovaries are half superior in rose, peach, and plum."
- The classification of flowers based on ovary position includes hypogynous (superior ovary), epigynous (inferior ovary), and perigynous (half inferior).
- Rose, peach, and plum have perigynous flowers, which means they have half inferior ovaries.
- **Conclusion**: This statement is also correct.

3. **Ovules in Exile Placentation**:
- The third statement states "ovules are born on the central axis in exile placentation."
- In axile placentation, ovules are indeed attached to the central axis of a multi-locular ovary.
- Examples include China rose, tomato, and lemon.
- **Conclusion**: This statement is correct.

4. **Placenta as Attachment Site**:
- The fourth statement says "placenta is the site of attachment of gynoecium in the flower."
- This statement is incorrect. The placenta is not the site of attachment for the gynoecium; rather, it is the site where ovules attach within the ovary.
- The gynoecium (the female reproductive part) is attached to the thalamus, not the placenta.
- **Conclusion**: This statement is incorrect.

### Final Answer:
The incorrect statement among the options is:
**D. Placenta is the site of attachment of gynoecium in the flower.**

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