Angiosperms (dicotyledons) were distinguished into Archichlamydeae and Metachlamydeae by

Options

A. Candolle
B. Cronquist
C. Hutchinson
D. Engler and Prantl

Answer

### Step-by-Step Solution:

1. **Identify the Classification**: Understand that angiosperms, specifically dicotyledons, are classified into two subclasses: Archichlamydeae and Metachlamydeae.

2. **Determine the Botanists**: Recognize that this classification was made by two German botanists, Adolf Engler and Karl Prandtl.

3. **Reference Their Work**: Note that Engler and Prandtl wrote a comprehensive work titled "The Natural Plant Families," which consists of 23 volumes.

4. **Understand the Division Structure**: In their classification, plants were divided into 13 divisions, with the 13th division specifically addressing gymnospermae and angiospermae.

5. **Differentiate Between Gymnospermae and Angiospermae**: Understand that gymnospermae refers to plants with naked ovules or seeds, while angiospermae refers to those with enclosed ovules or seeds.

6. **Classify Angiospermae**: Within angiospermae, there are two main classes: monocotyledone and dicotyledone.

7. **Subdivide Dicotyledone**: The dicotyledone class is further divided into the two subclasses: Archichlamydeae and Metachlamydeae.

8. **Define Characteristics**:
- **Archichlamydeae**: Flowers are aclamydous or mono/dichlamydous, with mostly free petals (polypetalous condition).
- **Metachlamydeae**: Features a gamopetalous condition, meaning the petals are fused.

9. **Conclude the Answer**: Therefore, the classification of angiosperms into Archichlamydeae and Metachlamydeae is attributed to Adolf Engler and Karl Prandtl.

### Final Answer:
Angiosperms (dicotyledons) were distinguished into Archichlamydeae and Metachlamydeae by Adolf Engler and Karl Prandtl.

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