Hi!
The tea tree's medicinal properties, referred to as tea tree oil, were discovered by the aboriginal people of Australia thousands of years ago. Supposedly, they crushed the leaves of the tree and applied them to cuts or burns as an antiseptic (http://health.howstuffworks.com/skin-care/problems/treating/improve-skin-with-tea-tree-oil.htm). Stories credit British explorer John Cook with the name "tea tree" after he observed native Australians brewing tea from the tea leaves in the 1700's (http://www.alive.com/health/the-healing-power-of-tea-tree-oil/).
The oil is distilled from the leaves of the tree Melaleuca alternifolia (http://health.howstuffworks.com/skin-care/problems/treating/improve-skin-with-tea-tree-oil.htm). According to the National Institutes of Health, tea tree oil is "applied to the skin (used topically) for infections such as acne, fungal infections of the nail (onychomycosis), lice, scabies, athlete’s foot (tinea pedis), and ringworm. It is also used topically as a local antiseptic for cuts and abrasions, for burns, insect bites and stings, boils, vaginal infections, recurrent herpes labialis, toothache, infections of the mouth and nose, sore throat, and for ear infections such as otitis media and otitis externa. Some people add it to bath water to treat cough, bronchial congestion, and pulmonary inflammation" (https://www.nlm.nih.gov/medlineplus/druginfo/natural/113.html).
-Kristen (Future Librarian)