Distribution: Occurring in Washington\'s coastal counties; Alaska to California along the coast; also on the Atlantic Coast.
Habitat: Sub-tidal area.
Conservation Status: Not of concern
Monoecious, submersed, aquatic perennials from extensive rhizomes, the stems branching, up to 2 m. long.
Leaves alternate, linear, basally sheathing, up to 12 dm. long and 3-12 mm. broad, the sheaths closed.
Inflorescence 1-sided, 3-6 cm. long, the staminate and pistillate flowers alternating in two rows on the fleshy axis; each staminate flower a single, sessile anther, quickly detached; each pistillate flower a single, 2-carpellary pistil with 1 style and 2 stigmas.
:Utricle about 4 mm. long, beaked, rounded at the base.