Catnip is a perennial best known for the minty odor emitted by its leaves and stems when they are crushed or wilted. The odor is very attractive to cats. Many of its uses are stress relieving in some form or another. Catmint is useful for a variety of digestive issues from stomach upset, diarrhea and gas. It may also help ease menstrual cramps. Many use catmint for respiratory issues such as cough and congestion.