No, an onion is not a tuber.
Understanding Onions and Tubers
An onion is a bulb, a specialized underground stem with layers of modified leaves. These leaves form the concentric rings we see when we cut an onion. Tubers, on the other hand, are thickened underground stems or roots that store nutrients. Think of potatoes – those are tubers. The key difference lies in their structure and development. The reference explicitly states that an onion is a bulb, not a tuber.
Several sources confirm this distinction:
- Reference 1: "The onion is a bulb, not a tuber, meaning that they are specially-formed, underground stem wrapped in modified leaves that form the bulb's layers."
- Reference 2: This source discusses the onion's bulb formation, further emphasizing that it's not a root vegetable.
- Reference 7: This confirms that an onion is a "converted underground stem known as the Tunicated Bulb."
- Reference 9: This source notes the similarity between a bulb and a tuber, but clearly indicates an onion is not a tuber.
While some sources might casually refer to onions and tubers together, their botanical classifications are distinct. Ginger, often mistakenly considered a tuber, is actually a rhizome.
In summary: The bulb of the onion is a modified stem, fundamentally different from the structure of a tuber.
