This remarkably patterned plant is a Ginger in the genus Costus. It is native to Macas, in Southern Ecuador. For a Ginger, it is on the slow side, and a little bit temperamental in my growing conditions. Given more room to grow, I suspect it would get a bit larger, but it is limited to about 18″ in its current enclosure.
Each leaf comes out a little different, with new growth being more purple, and developing more green mottling as the leaf matures.