Eucalyptus Leaf (Eucalyptus globulus). Eucalyptus may be used externally as a deodorant; in decaying, discharging wounds; in ulcers and in gangrenous or cancerous lesions. In respiratory infections such as bronchitis, eucalyptus is used as steam inhalation for its antiseptic and stimulatory effects. It is helpful in treating the flu, and pneumonia. As an oil, eucalyptus may be used for pyorrhea, burns and the prevention of infection. The most widely known medicinal use of eucalyptus oil is for respiratory ailments. CAUTION: Eucalyptus oil should NOT be used in large amounts over long periods of time since it is difficult to eliminate through the kidneys.