Acorn mint - Mentha arvensis L. 
Mint tea is to use both for digestion as for the respiratory system.
Traditionally, peppermint has been, and still is, used for colds and inflammations of the sinuses to disinfect the airways and keep them open. Peppermint and menthol do refresh the nose immediately, improving respiration and making you feel better. The effects on the airways depend on the composition of the essential oil used. Some ingredients are more expectorant and therefore more effective for a blocked nose.