Ectophloic siphonostele is found in

Options

A. Osmunda and Equisetum
B. Adiantum and Cucurbitaceae
C. Marsilea and Botrychium
D. Dicksonia and Maiden hair fern

Answer

To solve the question regarding where ectophloic siphonostele is found, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Term "Ectophloic Siphonostele":**
- Ectophloic siphonostele is a type of vascular arrangement in plants. It consists of a central pith surrounded by a ring of xylem, which is then surrounded by a ring of phloem.

2. **Identify the Structure:**
- In this structure, the pith is located at the center, the xylem forms a ring around the pith, and the phloem surrounds the xylem. This arrangement is characteristic of siphonosteles.

3. **Classify the Type of Stele:**
- The siphonostele is classified as a monosteel, which means it has a single vascular cylinder. This classification helps narrow down the types of plants that may exhibit this structure.

4. **Identify Examples of Plants:**
- Ectophloic siphonostele is specifically found in certain types of plants. The notable examples include **Osmunda** (a genus of ferns) and **Equisetum** (commonly known as horsetails).

5. **Choose the Correct Answer:**
- Based on the understanding that ectophloic siphonostele is found in Osmunda and Equisetum, we can conclude that the answer to the question is: **Osmunda and Equisetum**.

### Final Answer:
The ectophloic siphonostele is found in **Osmunda and Equisetum**.

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