Dry Mint Leaves are aromatic, almost exclusively perennial, rarely annual, herbs. They have wide-spreading underground rhizomes and erect, branched stems. The mint leaf, fresh or dried, is the culinary source of mint. Unfortunately, there aren't many human studies documenting the impact mint has on the body apart from digestion support and irritable bowel syndrome relief. With time, the research could confirm that mint is useful in treating a wider variety of illnesses.