It Should Really Be "What Is A Mullein?" Because A Mullein Is A Type Of Plant. Hope I Helped :)
You can use spearmint Herb, Wild Lettuce Herb, Red Clover Flowers Herb, Mullien Herb, Lobelia Herb,Damiana Herb, Calea Z Herb.
Oxygen and exercise do wonders for the respiratory system.
An old family remedy is to simmer a cloved onion in honey, as an expectorant. It improves with age but still tastes gacky. For a suppressant effect, we always used a few drops of mint (Peppermint is best for tummy complaints. Menthol crystals melted in honey is a strong suppressor, taking a teaspoon after every cough. Soon slows the coughs to nothing. Peppermint and spearmint oil could be used as well.) To open the bronchi and reduce swelling, Mullien leaf tea or smoking the dried leaf if it is an emergency (asthma, etc.) Good for sore throat is a strong Mullien leaf tea, added to honey to make a syrup, a spoonful an hour. My grandmother always had a bottle of her Mullien leaf tea and drank a 1/3 cup, cold, daily to ward of asthma, especially muggy weather asthma. To get a jump on allergies before the season starts, a syrup of mullein and "flore saco" (sp?) which is dried Elderberry blossoms is made and taken by spoonful several times a day, orange, lime or lemon juice help the sore throat, and improve the rather bland taste. I'm NOT a Dr. these are remedies weve had in the family for generations. Works for us!