What is the source of cocaine?

Explanation

**Step-by-Step Solution:**

1. **Identify the Substance**: The question asks for the source of cocaine, which is a well-known stimulant.

2. **Classify Cocaine**: Cocaine is classified as a tropane alkaloid. This classification helps in understanding its chemical structure and properties.

3. **Source of Cocaine**: The primary source of cocaine is the plant known as *Erythroxylum*. It is important to note that cocaine is derived specifically from certain parts of this plant.

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