Sagittaria teres, the quill-leaved arrowhead or slender arrowhead, is an aquatic plant species of arrowhead native to the northeastern United States: Rhode Island (Providence and Washington Counties), Massachusetts, New Hampshire (Hillsborough County), New York (Suffolk County) and New Jersey. Sagittaria teres grows along the shores of lakes, marshes, and other wetlands, frequently those with acidic water such as Sphagnum bogs.