calathea lancifolia 
'Rattlesnake Plant'
 
This plant prefers a light indirect spot indoors, too much direct sunlight and the foilage may become faded. For watering, think "water little & often" - they like their soil kept moist but they are not happy when left in soggy soil or sitting in a saucer of water. They like warm & humid environments but can fair well in a slightly colder than room temperature condition. 
 
20cm