(Melaleuca Alterifolia) This oil is unusual in that it is active against all three varieties of infectious, organisms: bacteria, fungi and viruses. It is a very powerful immuno-stimulant, so when the body is threatened by any of these organisms – tea tree increases its ability to respond. Blends well with Lavender ClarySage, Rosemary, Pine, Geranium, Marjoram and Spice Oils.