In the book 'Historia Plantarum' plant classification is based on

Options

A. Economic importance
B. Habit
C. Sexual character
D. Evolutionary trends

Answer

**Step-by-Step Solution:**

1. **Identify the Author and Context**: The book 'Historia Plantarum' was written by Theophrastus, who is known as the father of botany.

2. **Understand Theophrastus' Classification Method**: Theophrastus classified plants based on their physical characteristics, particularly their habit. He categorized them into different groups such as trees, shrubs, subshrubs, and herbs.

3. **Analyze the Options Provided**:
- **Option A: Economic Importance** - This was not the basis for Theophrastus' classification.
- **Option B: Habit** - This is the correct answer as it aligns with Theophrastus' classification method.
- **Option C: Sexual Character** - This was not a focus in his classification.
- **Option D: Evolutionary Trends** - This concept was not part of Theophrastus' classification.

4. **Conclude the Correct Answer**: Based on the analysis, the correct answer is **Option B: Habit**.