I found this plant growing in a pot in my backyard. It smells medicinal similar to camphor... Menthol... Eucalyptus. If it is melaleuca then I suppose it is best to destroy it. (?) It is healthy and growing fast.
It does appear that you have a Melaleuca tree. This is an invasive plant. You can learn a little more about the tree and its control at: http://edis.ifas.ufl.edu/ag241 If you have any more questions, there are horticulturists and Master Gardener Volunteers at the Pinellas County Extension Service. They can be found at: 12520 Ulmerton Rd. Largo, FL 33774. Their phone number is 727-582-2100. Have a great gardening weekend.