Dried leaves and flowers from the thyme plant.
The ancient Greeks used it in their baths and burnt it as incense in their temples, believing it was a source of courage. The spread of thyme throughout Europe was thought to be due to the Romans, as they used it to purify their rooms and to "give an aromatic flavor to cheese and liqueurs". In the European Middle Ages, the herb was placed under pillows to aid sleep and ward off nightmares. In this period, women would often give knights and warriors gifts that included thyme leaves, as it was believed to bring courage to the bearer. It is used widely as a seasoning in culinary.
While a hot drink made by boiling the herb in water, calms, effectively, flu symptoms.