Select an incorrect statement.

Options

A. In marginal placentation the ovules are borne on the ridge forming two rows.
B. When the ovules are borne on central axis and septa are absent the placentation is free central.
C. In basal placentation, the placenta develops at the base of ovary
D. False septum is found in mustard, Primrose and Argemone

Answer

To solve the question of selecting an incorrect statement regarding placentation in flowering plants, we will analyze each statement one by one.

### Step-by-Step Solution

1. **Evaluate the First Statement**:
- The first statement claims that in marginal placentation, the ovules are born on the ridge forming two rows.
- This statement is **correct** because marginal placentation indeed involves ovules developing along the margin of the ovary, forming two rows.

**Hint**: Recall the definition of marginal placentation and visualize the ovule arrangement.

2. **Evaluate the Second Statement**:
- The second statement states that when ovules are born on the central axis and septa is absent, the placentation is free central.
- This statement is also **correct**. Free central placentation occurs when ovules are attached to a central column without any septa.

**Hint**: Think about the structure of the ovary and how the ovules are positioned in free central placentation.

3. **Evaluate the Third Statement**:
- The third statement mentions that in basal placentation, the placenta develops at the base of the ovary.
- This statement is **correct** as well. In basal placentation, the ovules are attached at the base of the ovary.

**Hint**: Visualize the ovary structure and where the placenta is located in basal placentation.

4. **Evaluate the Fourth Statement**:
- The fourth statement claims that false septum is found in mustard, primrose, and argimon.
- This statement is **incorrect**. While false septum is found in mustard and argimon (which have parietal placentation), it is absent in primrose, which has a tricentral placentation.

**Hint**: Recall the characteristics of each plant mentioned and their respective placentation types.

### Conclusion
After evaluating all the statements, the incorrect statement is **option number 4**.

### Final Answer
The answer is **option number 4**.

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