Narrow-leaved plantain (Plantago lanceolata L.) is particularly abundant in southern areas of British Columbia, Ontario and Quebec, and the coastline of Prince Edward Island and Nova Scotia. It is a serious weed of lawns, dry grasslands and roadsides, although it is a palatable species to livestock in dry pastures. This account is a summary of the most recent biological information on P. lanceolata including data heretofore unpublished.