The Indians of Central Mexico and Guatemala had medicinal uses for the dahlia [besides growing it as a root crop]. Dahlia extracts were employed to treat epilepsy, but also rashes, infected grazes and cracks in the skin. In the past, dahlia petals were crushed and mashed up, and then used to soothe insect bites or stings. A manuscript found in Mexico also recorded the use of a preparation of dahlia stems to treat urinary-tract disorders.
Even today, the juice extracted from dahlia tuber is used to help cleanse liver and kidneys.