Lavender
For thousands of years, this pretty, flowering herb has been used medicinally to calm nerves, relieve headaches, ease labor pains, prevent insomnia and aid in depression. (It’s soothing scent is still a mainstay in aromatherapy treatments.) While countless scientific studies have vouched for its effectiveness, a particularly illuminating 2009 study discovered that the scent of lavender had tangible effects on lowering pulse rates on nursing students in stressful situations.