This plant was collected in the Rio Nangaritza area of southeastern Ecuador. I thought it was the species C. zamoranus, but after further research and study of the detailed characters I have now concluded this to be the species Costus amazonicus subspecies amazonicus. Further discussion of this is on my main website at http://www.gingersrus.com/DataSheet.php?PID=7467.
The plant matures to about 4 feet tall and I have had it flower both basally and terminally, with green bracts and creamy white flowers with red stripes on the labellum. It has not been tested for hardiness but probably needs to be protected from temperatures below 40 degrees Farhenheit.