Which of the following are not characteristic features of fabaceae ?
(a) Top root system , compound leaves and raceme inflorescence
(b) Flowers actinomorphic , twisted aestivation and gamopetalous
(c) Stamens ten, introrse , basifixed and dithecous
(d) Monocarpellary , ovary superior and bent stigma

Options

A. Top root system , compound leaves and raceme inflorescence
B. Flowers actinomorphic , twisted aestivation and gamopetalous
C. Stamens ten, introrse , basifixed and dithecous
D. Monocarpellary , ovary superior and bent stigma

Answer

To solve the question regarding the characteristic features of the Fabaceae family, we need to analyze each option given in the question.

### Step-by-Step Solution:

1. **Understanding the Characteristics of Fabaceae:**
- The Fabaceae family, also known as the legume family, has specific features that are generally accepted in botanical classification.

2. **Analyzing Option (a):**
- **Top root system:** Fabaceae plants typically have a taproot system.
- **Compound leaves:** Leaves in this family are usually compound.
- **Raceme inflorescence:** While raceme inflorescence can occur, many Fabaceae plants exhibit other types of inflorescence, such as racemose or umbellate. However, this option does not contain incorrect features.
- **Conclusion:** This option is characteristic of Fabaceae.

3. **Analyzing Option (b):**
- **Flowers actinomorphic:** Flowers in Fabaceae are typically zygomorphic (bilaterally symmetrical), not actinomorphic (radially symmetrical).
- **Twisted aestivation:** This is not a common feature in Fabaceae; they usually exhibit valvate or imbricate aestivation.
- **Gamopetalous:** Fabaceae flowers are usually polypetalous (free petals), not gamopetalous (fused petals).
- **Conclusion:** This option contains incorrect features and is the answer to the question.

4. **Analyzing Option (c):**
- **Stamens ten:** This is a characteristic feature of Fabaceae.
- **Introrse:** The stamens are indeed introrse.
- **Basifixed:** This is also true for the stamens in this family.
- **Dithecous:** This is a correct description as well.
- **Conclusion:** This option is characteristic of Fabaceae.

5. **Analyzing Option (d):**
- **Monocarpellary:** Fabaceae flowers typically have a single carpel.
- **Ovary superior:** This is correct for Fabaceae.
- **Bent stigma:** The stigma is often curved, which is a characteristic feature.
- **Conclusion:** This option is characteristic of Fabaceae.

### Final Answer:
The option that is **not a characteristic feature of Fabaceae** is **(b) Flowers actinomorphic, twisted aestivation, and gamopetalous.**

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