Wild Oregano (Origanum Vulgare ) is a perennial herb that has purple flowers and spade-shaped, olive-green leaves. The whole plant has a strong, peculiar, fragrant, balsamic odour and a warm, bitterish, aromatic taste, both of which properties are preserved when the herb is dry. The oregano sold as a spice is either Sweet Marjoram (Origanum majorana) or Mexican Sage. There are over 40 oregano species, but the most therapeutically beneficial is the wild oregano or Origanum vulgare that's native to Mediterranean mountains. To obtain oregano oil, the dried flowers and leaves of the plant are harvested when the oil content of the plant is at its highest, and then distilled.