Two genera that produce racemose and cymose inflorescences respectively are

Options

A. Crotalaria and Allium
B. Ipomoea and Helianthus
C. Crotalaria and Ipomoea
D. Allium and Helianthus

Answer

To answer the question about two genera that produce racemose and cymose inflorescences respectively, we can follow these steps:

### Step 1: Understand the Types of Inflorescences
- **Racemose Inflorescence**: This type of inflorescence has a main axis that continues to grow, and flowers are borne laterally along this axis. The flowers bloom from the bottom upwards, allowing for continuous growth.
- **Cymose Inflorescence**: In this type, the main axis terminates in a flower, and growth occurs laterally. The flowers bloom from the top downwards, leading to a more compact arrangement.

**Hint**: Remember the key characteristics of racemose and cymose inflorescences to differentiate between them.

### Step 2: Identify Genera with Racemose Inflorescence
- One example of a genus that exhibits racemose inflorescence is **Crotalaria**. In this genus, flowers are arranged along the sides of a continuously growing stem.

**Hint**: Look for plants that have a tall growth habit with flowers developing along the sides.

### Step 3: Identify Genera with Cymose Inflorescence
- An example of a genus that exhibits cymose inflorescence is **Ipomoea**. In this genus, the flowers are arranged in a way that the main stem ends in a flower, and lateral growth occurs.

**Hint**: Consider plants that have a more compact structure with flowers developing at the tips.

### Step 4: Conclusion
Based on the above analysis, the two genera that produce:
- **Racemose Inflorescence**: Crotalaria
- **Cymose Inflorescence**: Ipomoea

Thus, the answer to the question is:
- **Crotalaria** for racemose inflorescence
- **Ipomoea** for cymose inflorescence

**Final Answer**: Crotalaria (racemose) and Ipomoea (cymose).