Oregano

From the pages of Wikipedia:
Oregano or Pot Marjoram (Origanum vulgare) is a species of Origanum, native to Europe, the Mediterranean region and southern and central Asia. It is a perennial herb, growing to 20-80 cm tall, with opposite leaves 1-4 cm long. It has an aromatic, warm and slightly bitter taste.

The related species Origanum onites (Greece, Asia Minor) and O. heracleoticum (Italy, Balkan peninsula, West Asia) have similar flavours. A closely related plant is marjoram from Asia Minor, which, however, differs significantly in taste, because phenolic compounds are missing in its essential oil. Some breeds show a flavour intermediate between oregano and marjoram.

The dish most associated with oregano is pizza. Its relatives have probably been eaten in Southern Italy for centuries.