Lemongrass is a plant. The leaves and the oil are used to make medicine. Lemongrass is used for treating digestive tract spasms, stomachache, high blood pressure, convulsions, pain, vomiting, cough, achy joints (rheumatism), fever, the common cold, and exhaustion. It is also used to kill germs and as a mild astringent. With its lemony scent and hint of rose aroma, lemongrass is an essential ingredient in Thai and Indonesian cooking. Lemongrass grows wild in Indonesia, Indochina, and tropical Australia, and has been cultivated in Southeast Asia and Sri Lanka as a culinary herb and in India as a medicinal herb for thousands of years.