Both, Citronella (Cymbopogon Nardus) and Lemongrass (Cymbopogon Citratus) are cousins in nature. They look similar and grow the same way. They are also processed in the same manner to obtain essential oils. But, Citronella is not for consumption while Lemongrass can be consumed or used as a herbal tea. To distinguish between them, remember that Citronella has pseudostems (false stems) that are reddish in colour while Lemongrass stalks are green.