From Wikipedia 
Cymbopogon (lemongrass) is a genus of about 55 species of grasses, (of which the type species is Cymbopogon citratus) native to warm temperate and tropical regions of the Old World and Oceania. It is a tall perennial grass. Common names include lemon grass, lemongrass, barbed wire grass, silky heads, citronella grass,cha de Dartigalongue, fever grass, tanglad, hierba Luisa or gavati chaha amongst many others.
Varieties are much used in cooking, perfumery and herbal products, and as a component of teas.