Keel is the characteristic feature of flower of

Options

A. Indigofera
B. Aloe
C. Tomato
D. Tulip

Answer

### Step-by-Step Solution:

1. **Understanding the Term "Keel":**
- The keel refers to a specific structure in certain flowers, particularly those belonging to the family Fabaceae (also known as Leguminosae). It is formed by the fusion of two petals that are located at the bottom of the flower.

2. **Identifying the Family:**
- The flowers that exhibit a keel structure are typically found in the family Papilionaceae (a subfamily of Fabaceae). This family is known for its butterfly-shaped corolla.

3. **Characteristics of the Keel:**
- In flowers of the Papilionaceae family, the keel is the innermost petal, which is fused and encloses the stamens and carpels. The outermost petal is the largest and is called the vexillum, while the two lateral petals are referred to as wings.

4. **Examples of Plants with Keel:**
- Common examples of plants with a keel include beans, peas, and grams. These plants have flowers that showcase this unique petal arrangement.

5. **Analyzing the Options:**
- The question provides several options: Indigofera, Aloe, Tomato, and Tulip. Among these, Indigofera is known to belong to the Fabaceae family and thus possesses the keel structure.

6. **Conclusion:**
- Based on the characteristics and the family association, the correct answer to the question "Keel is the characteristic feature of flower of" is **Indigofera** (Option A).