In which of the following Pollinia are formed ?

Options

A. Zostera
B. Mirabilis
C. Vallisneria
D. Calotropis

Answer

To determine in which of the following options polinia are formed, we need to first understand what polinia are and then analyze each option provided.

### Step-by-Step Solution:

1. **Understanding Polinia**:
- Polinia are clusters of pollen grains that are joined together. They are typically found in certain flowering plants, particularly in the family Orchidaceae (orchids) and some other plants like Calotropis.
- Polinia facilitate the process of pollination, often through mechanisms that involve wind or specific pollinators.

2. **Analyzing the Options**:
- **Option 1: Zoostera**:
- Zoostera is an aquatic plant (commonly known as eelgrass) and does not produce polinia. Therefore, this option is incorrect.
- **Option 2: Mirabilis**:
- Mirabilis (commonly known as four o'clock flower) produces individual pollen grains rather than clusters. Thus, this option is also incorrect.
- **Option 3: Valesinaria**:
- Valesinaria is another aquatic plant and does not form polinia. Hence, this option is incorrect as well.
- **Option 4: Calotropis**:
- Calotropis (commonly known as milkweed) is known to produce polinia. It has clusters of pollen grains that are characteristic of this plant. Therefore, this option is correct.

3. **Conclusion**:
- The correct answer is **Calotropis**, as it is the only option that forms polinia.

### Final Answer:
**Calotropis**

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