Which of the following is not a Basidiomycetes ?

Options

A. Agaricus
B. Ustilago
C. Aspergillus
D. Puccinia

Answer

To determine which of the following options is not a Basidiomycetes, we need to analyze each option based on their classification in the fungal kingdom.

### Step-by-Step Solution:

1. **Understand Basidiomycetes**:
- Basidiomycetes, also known as club fungi, are a class of fungi characterized by the presence of septa (cross-walls) in their hyphae and the formation of basidiospores exogenously. They typically do not have sex organs and have clamp connections between adjacent cells.

2. **Examine the Options**:
- **Option 1: Agaricus**:
- Agaricus is a genus that includes mushrooms, which are indeed classified under Basidiomycetes. Therefore, this option is incorrect as it is a Basidiomycete.

- **Option 2: Stilago**:
- Stilago is a genus that includes wheat rust fungi, which are also classified as Basidiomycetes. Thus, this option is also incorrect.

- **Option 3: Aspergillus**:
- Aspergillus is a genus of fungi that belongs to the Ascomycetes class, which produces ascospores. This means that Aspergillus is not a Basidiomycete, making this option a potential correct answer.

- **Option 4: Paxinia**:
- Paxinia, specifically Paxinia graminis, is a type of rust fungus and is classified under Basidiomycetes. Therefore, this option is incorrect.

3. **Conclusion**:
- After analyzing all the options, the only organism that is not a Basidiomycete is **Aspergillus**.

### Final Answer:
**Aspergillus** is not a Basidiomycetes.

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