Can you tell me what this is?

I bought this plant and the label just said "tropical plant". Since I planted it in a large pot, it has grown about 2 feet and blooms constantly. I would like to know what it is so I can find out how to care for it.

 

Probably a Ruellia sp.
Family: Acanthaceae

 

I agree, looks like wild petunia or Mexican petunia - Ruellia.
http://images.google.com/images?hl=en&q=Mexican petunia&btnG=Google+Search&sa=N&tab=wi

Newt

 

Thanks for the information. That's exactly what it is!

 

It is Ruellia tuberosa