» For the European Agency, see European Agency for Safety and Health at Work, (EU-OSHA).:For the U.S. government agency, see Occupational Safety and Health Administration. Osha or oshá (Ligusticum porteri)'s a perennial herb used for its medicinal properties. Osha grows in parts of the Rocky Mountains, especially in the North American Southwest. Uses include chewing to relieve sore throat. Distribution Osha's strictly a mountain plant, and it's most commonly found in deep, moist soils rich… (More on Osha)