Picloram is a pyridinemonocarboxylic acid, specifically pyridine-2-carboxylic acid substituted with a chloro group at positions 3, 5, and 6, and an amino group at position 4. It is a systemic herbicide used to control deeply rooted herbaceous weeds and woody plants in rights-of-way, forestry, range lands, pastures, and small grain crops. It functions as a herbicide and a synthetic auxin, and is classified as an aminopyridine, chloropyridine, organochlorine pesticide, and is functionally related to picolinic acid.