There is a stem modification in Ruscus. It is

Options

A. Cladode
B. Phylloclade
C. Thorn
D. Corm

Answer

### Step-by-Step Solution:

1. **Understanding Stem Modifications**:
- In plants, stems can undergo modifications to adapt to their environment. These modifications can serve various functions such as photosynthesis, storage, or protection.

2. **Identifying the Options**:
- The options given are: Cladode, Phyloclade, Thorn, and Comb. We need to determine which of these is the stem modification found in Ruscus.

3. **Defining Phyloclade**:
- A phyloclade is a green, photosynthetic, flattened or rounded succulent stem. It may have leaves that are either present or modified into spines. An example of a phyloclade is Opuntia.

4. **Defining Cladode**:
- A cladode is a succulent stem that usually has one or two internodes. It is also photosynthetic and can be found in plants like Asparagus and Ruscus.

5. **Defining Thorn**:
- Thorns are modified stems that are spiny or pointed, commonly found in cacti. They serve as a protective mechanism.

6. **Defining Comb**:
- A comb is a swollen stem that is primarily used for food storage, with Gladiolus being an example.

7. **Conclusion**:
- Since Ruscus is known to have a stem modification that is a succulent stem with one or two internodes, the correct answer is "Cladode."

### Final Answer:
The stem modification in Ruscus is known as **Cladode**.

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