Oregano

Source= Leaves of the oregano plant, Origanum vulgare
Flavor=Similar to marjoram, but not as sweet
Best used=Fresh or dried
Cooking use=In Italian dishes, in chili, with vegetables, soups

This herb contains two essential components, thymol and carvacol, which are also found in another herb, thyme. Thymol can be used to help loosen phlegm in the lungs, according to Norman R. Farnsworth, Ph.D., director of the Program for Collaborative Research in the Pharmaceutical Sciences at the University of Illinois at Chicago. In Germany, where herbal medicine is popular, syrups containing thymol are frequently prescribed for even the most serious kinds of coughs. In the United States, you're most likely to find thymol in cough remedies such as Vicks Menthol Cough Drops and in topical cough and cold products such as Vicks VapoRub. The ingredients in oregano that soothe coughs also help unknot muscles in the digestive tract.