Citronella looks like Lemongrass (scientific name: Cymbopogon citratus) but it has a wider leaf blade and the base of the stem (technically known as a pseudostem) is reddish, while Lemongrass has a green one. It is a species of perennial aromatic plant and the source of an essential oil known as citronella oil, which is widely used for its natural insect-repelling properties.