Oregano is the dried leaves of Origanum vulgare and is generally grown in Turkey and Greece. It has a warm, zesty, slightly bitter flavor. It is the staple herb of Italian-American cuisine with popularity dating back to World War II. It combines well with spicy food, making it more popular in Southern Italian cuisine, while its close relative, marjoram is more popular in Northern Italian cuisine. Often times it is used with roasted, fired, or grilled vegetables, meat, and fish.