Melaleuca are part of the Myrtle family and are closely related to the Bottle Brush - Callistemon. It is an enormous genus but very few are really hardy. Below is a small selection of those I would feel comfortable growing outside in most gardens. As with all Myrtaceae, nuetral to acid soil is preferred, water in well when planting and always prune after flowering to maintain a good shape. 

Melaleuca

Melaleuca gibbosa