There are over 700 different species of Eucalyptus, with about 500 of which are able to produce an essential oil. Some reports state that only fifteen species occur outside Australia, with just nine of these not occurring in Australia. Though with only a few that produce essential oils - these oils are universally well known for their medicinal or perfumery applications. Of each Eucalypt, the quantity and quality of essential oil produced varies greatly, due to a different chemical fingerprint with variations in the constituents within the oil.