It is sweet in flavour and cold in nature. It is tropistic to the lung channel. Its sweetness and coldness are good at clearing and sending down rebellious Qi. It acts solely in the lung channel. It can purge lung-heat, send down adverse lung-qi, relieve cough and asthma, thus it is indicated in accumulation of lung-fire, cough and asthma by rebellious Qi. It is able to purge lung-heat, send down adverse Qi, and to promote diuresis, eliminate edema to cure patients with edema and dysuria.