Types of Oregano
To most Americans, oregano is simply the seasoning on pizza or spaghetti. But to botanists, the word oregano can be a real headache. More than 40 plants in four botanical families go by the name oregano. Many have similar taste but have different medicinal qualities and different potencies. Thus oregano more properly refers to a flavor rather than one particular plant.
What is more commonly called oregano are those plants which belong to Labiatae or mint family, and are of the genus Origanum. There are about 25 species of Origanum. True oregano, as used for medicinal purposes, is confined to several species of wild oregano plants.
The "oregano" spice which most people use is more correctly called marjoram (Origanum majorana). It is also called sweet marjoram as it has a sweeter and more mild taste and is somewhat more piquant than oregano. Its leaves are one-fourth to one inch long and oval shaped. The calyx is one-lipped with a deep slit. Its flowers are one-eighth-inch long and white or pink. The plant reaches a height of two feet.
The oregano spice that comes from the WEst coast and Mexico, called Mexican oregano, is actually a sage classed as Lippia graveolens of the Verbena family. It is not true oregano but has the oregano flavor. Likewise, that which is called "Spanish oregano" is strictly a thyme and not a true medicinal oregano.
The species Origanum vulgare often called wild marjoram is a true oregano, and has stronger medicinal qualities than marjoram. It is reddish-brown and grows to two and a half feet tall. Its leaves are oval, toothed and up to one and a half inches long. The flowers are white-purple and about one-fourth-inch long. It has a calyx with five even teeth. This oregano is a native of Britain, Europe, Asia and North Africa.
Origanum heracleoticum is also a true oregano and similar to O.vulgare. It is sometimes referred to as winter marjoram and is native to southeast Europe (Italy, Greece, Turkey). The bracts are usually one-eighth inch long, are densely covered with oil glands on the lower surface, and are generally green.
Origanum onites, often called pot marjoram, is a hairy plant growing to two feet in height. The leaves are oval or rounded one-fourth to three-fourths inch long, and sparsely toothed. The flowers are in a dense terminal cluster up to three inches across. The bracts are pointed and about one-eighth-inch long. Pot marjoram is a Mediterranean native.
Origanum dictamnus is a native of Crete and has strong medicinal qualities. It is a tender perennial growing to a foot in height. The flowers are pink and about one-half inch long.