An herb is a plant whose leaves, seeds, or flowers are used for flavoring food or in medicine. Other uses of herbs include cosmetics, dyes, and perfumes. The name derives from the Latin word herba, meaning “green crops.”

Oregano is a collection of perennials in the mint family. The most common include Greek oregano (Origanum vulgare hirtum or Origanum heracleoticum), Italian oregano (Origanum majoricum), Cretan oregano (Origanum onites), and Syrian oregano (Origanum syriacum). Note that the genera names Origanum and Marjorana are used interchangeably by some, and that the herb Marjoram (Origanum marjorana) is in the same family.

For several reasons, there is a great deal of confusion in distinguishing marjoram from oregano. For one thing, they have the same genus, Origanum, while the species differ. For another thing, people call them by each other’s names:

• Greek oregano, O. vulgare, is called not only wild marjoram, but also Spanish thyme.
• Cretan oregano, O. onites, is also called pot marjoram or French marjoram.
• Marjoram, O. marjorana, is also called pot marjoram.
• O. heracleoticum is sometimes known as winter marjoram.

So, you can see how confusing this may become. Marjoram and oregano have more than species and similarity of flavor in common. A USDA analysis showed that these two culinary herbs have the highest amount of antioxidants, and more when they’re fresh than when they’re dried.

But there are differences, too. Oregano is a hardy perennial, while marjoram is more sensitive; oreganos may grow taller than marjoram. Also, marjoram prefers the soil slightly damper.

Another confusion arises between the oreganos mentioned above and Mexican oregano (Lippia graveolens or Lippia berlandieri). Mexican oregano is used similarly to oregano, but is actually an herb from a different family, with a similar taste but a higher amount of essential oil. There are other herbs that are called oregano, as well, in other parts of the world.

Description. The height and flowering characteristics of oregano vary a bit with each species. Greek oregano grows to about 18 to 24 inches (46 to 61 cm), and has white flowers, which bloom from June to August. The leaves are grey-green.

Gardening. The plant spreads assiduously and can be propagated by division. While Greek oregano can grow in poor soil, it does not do well in wet soil. If the plant becomes woody, it can be cut back and will re-grow. Leaves can be used fresh, or dried and kept in an air-tight container. Oregano is often recommended for companion planting.

Food and Other Uses. Mexican oregano is found in chili powders, chili, and Latin American dishes. The other oreganos, particularly Greek oregano, is likely to be found in other commercial herb blends. Unless you have access to the various subspecies, Greek oregano is likely the one you would wish to use for Italian dishes such as tomato sauces and pizza, Greek meat and casserole dishes, Middle Eastern dishes, Spanish dishes, and French dishes. It is widely used in salad dressings, with vegetables, and in a number of strongly flavored dishes from a variety of cuisines.