Thyme. Great not only for cooking.

Thyme is known as a remedy against a lot of respiratory problems: cough, chest congestion, bronchitis and other.
Its also boost immune system, lower blood pressure and its a powerful antioxidant.
Besides, this wonderful herb contain a vast amount of vitamins: thyme is an excellent source of vitamin C (75% of the daily recommended value), vitamin A (27%), fibre (16 %), riboflavin, iron (27%), copper, and manganese (24%), 11% each in calcium and manganese, and doses of vitamin B6, folate, phosphorus, potassium, and zinc as well.
That why I always add it to my herb tea.