The eucalyptus plant is native to Australia. It is an evergreen tree that can grow very tall - as high as 300 feet. It has green leaves. The leaves can be harvested year round. The tree requires large amounts of water to grow and can deprive surrounding plants of the necessary nutrients. Eucalyptus has been used by the Aboriginal people of Australia as a medication for respiratory infections. It's now used commonly in medications that are used to treat cough and cold symptoms.