Coastal Arrowhead

Sagittaria graminea, the coastal arrowhead or grass-leaved arrowhead, is an aquatic or semi-aquatic perennial herb in the family Alismataceae native to wetland habitats across a wide geographic range including eastern North America, parts of Asia including China and Japan, and isolated populations in Europe. The species inhabits shallow water margins, muddy shores, freshwater marshes, slow-moving streams, ditches, and pond edges, where it often forms dense emergent colonies. Sagittaria graminea is distinguished from other arrowheads by its narrow, grass-like submerged and emergent leaves that lack the pronounced arrowhead shape characteristic of the genus when leaves are fully emergent, though aerial leaves may have small basal lobes. The plant produces white three-petaled flowers arranged in whorls on tall flowering stems, with male flowers above and female flowers below. It is assessed as Not Evaluated by the IUCN. The tubers of arrowheads have historically been consumed as a starchy food by Indigenous peoples across North America. The species provides important habitat structure for aquatic invertebrates and waterfowl, and waterfowl consume the seeds and tubers. The name Sagittaria derives from the Latin for arrow, reflecting the classic arrowhead leaf shape seen in other species of the genus.