East Indian lemongrass (Cymbopogon flexuosus), also called Cochin grass or Malabar grass, is native to Cambodia, Vietnam, Laos, India, Sri Lanka, Burma, and Thailand, while West Indian lemongrass (Cymbopogon citratus) is native to maritime Southeast Asia. While both can be used interchangeably, C. citratus is more suitable for cooking.
Lemongrass Oil (aromatherapy)
Lemongrass Oil is a yellow or amber-colored, somewhat viscous liquid with a very strong, fresh- grassy lemon-type, herbaceous or tea-like odor.
Arctander, Steffen . Perfume and Flavor Materials of Natural Origin (p. 412).