The Rattlesnake Plant is a variety of the Calathea family that has one of the narrowest leaf structures.
Most of the Calathea varieties prefer fairly bright, but indirect sunlight. They will tolerate low light rooms, but the plant may experience slightly wilted leaves and a slower growth rate. Ideal place is close to a window or in a well lit room.
Try not to dry out the soil to much, or the Calathea lancifolia will start to wilt. Keep the soil constantly moist, but be sure not to overwater. Allow plenty of drainage to stop the plant sat in stagnant water.
Calathea lancifolia plants tend to splay outwards more than grow up, but can reach sizes of around 60-70cm.