Difference between lemongrass and citronella. Citronella is a variety of plants from the genus Citronella, represented by the species lemongrass Cymbopogoncitratus, which has a lemon citrus or mosquito repellent flavor. Botanical Name. Citronella, genus Citronella, family Gramineae, persistent herb. One or two feet high, the leaves are tufted, with parallel veins, and the leaf sheaths are glabrous. Before the leaves are borne, the top of the stem is densely covered with white hairy spikes, panicle. Its roots are sweet in flavor and can be used as medicine.