What is the leaf contained by onion?

Onions don't have leaves in the traditional sense. The part of the onion we eat is actually a bulb, which is an enlarged, underground stem. The true leaves of the onion plant are the long, green, hollow tubes that grow above ground.

Here's a breakdown:

* Bulb: This is the edible part of the onion. It's formed by the swollen bases of the leaves.

* Leaves: These are the green, hollow tubes that grow above ground and are responsible for photosynthesis.

* Stem: The stem is underground and is the base of the onion bulb.

So, while the bulb looks like a leaf, it's actually a modified stem.