Which of the infloresence does not bear bisexual flowers

Options

A. Catkin
B. Capitulum
C. Umbel
D. Raceme

Answer

**Step-by-Step Solution:**

1. **Understanding Bisexual Flowers:**
- Bisexual flowers are those that contain both male (stamens) and female (pistils) reproductive organs within the same flower.

2. **Defining Inflorescence:**
- Inflorescence refers to the arrangement of flowers on a plant. Different types of inflorescences can bear different types of flowers.

3. **Analyzing Catkins:**
- Catkins are a type of inflorescence that is spike-like and typically contains unisexual flowers, meaning they have either male or female reproductive organs, but not both. Examples include cottonwood and oak.

4. **Examining Other Inflorescences:**
- **Umber:** This inflorescence consists of many short flower stalks (pedicels) that arise from a common point, resembling an umbrella. It can bear bisexual flowers.
- **Capitula:** This inflorescence is characterized by a dense cluster of flowers that appear to form a single flower. It can also bear bisexual flowers, as seen in dandelions.
- **Raceme:** This is an unbranched, indeterminate inflorescence with short floral stalks (pedicels) that can bear bisexual flowers.

5. **Conclusion:**
- The only inflorescence that does not bear bisexual flowers is the **catkin**, as it exclusively contains unisexual flowers.

**Final Answer:**
The inflorescence that does not bear bisexual flowers is the **catkin**.

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