Anise

This is a flowering plant that grows around the Mediterranean. It has a flavor similar to black licorice, and it often used for that specific flavoring. The flavor comes from a compound called anethole, which it shares with fennel.

In my experience, the Greek liquor Ouzo is heavily flavored with anise.

Why I Looked It Up

It was the answer a clue in the NY Times. I believe the clue was:

Black licorice flavoring