Lemongrass is a genus of perennial grasses that actually includes about 55 species, native to Australia, Southeast Asia, and Africa. It grows as a perennial in warm climates. Lemongrass is used to make tea, curries, and soups; it's oil can also be used as a pesticide and a preservative. While the tender inner heart of the grass is most prized for cooking, the tougher part of the stalk can also be used in teas and soup stock. Fresh lemongrass can be stored in the refrigerator, where it dries out after 2 weeks, or the freezer, for up to 6 months. Dried lemongrass works well for stock or tea.