Marjoram and oregano are mostly native to the Mediterranean region, but have been naturalized in many parts of the world. The two names are interchangeable, and both names are still used to describe the bought herb and cultivars of the wild plant. Sweet marjoram, Origanum majorana, is less hardy than other varieties, and is considered to have the best flavor. Flowers are white, the leaves are pale green and round, and easy to dry for use in cooking. It’s best grown as an annual in cooler climates.