Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Atlantic Coast.

Habitat: Often in acidic waters, lakes, slow streams, sloughs, marshes.

Flowers: June-August

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Wind

Herbaceous wetland perennial; cauline stems round to slightly compressed, spots absent, up to 150 cm, glands present on some or many nodes, to 0.5 mm diameter; turions common, soft, lateral or terminal, 0.9-3.2 cm long and 0.3-1.8 mm broad.

Leaves submersed, generally spirally arranged, sessile, fine to coarse; stipules persistent, inconspicuous, convolute, blade 0.9-5.4 cm long and 0.2-2.5 mm broad, linear, not curved, base somewhat tapered, lobes absent and not clasping, margins entire and not wavy, apex subulate to obtuse, not hoodlike, lacunae in 1-5 rows on each side of midrib, veins usually 1-3.

Inflorescence an unbranched, capitate to cylindric spike, 1.5-10.1 mm, above or below water surface; peduncles more than 3 per plant, terminal or emerging from axils, erect, uncommonly curved backward, cylindric to slightly clavate, more than 3 per plant.

Tepals 4, in 1 series; stamens usually 4, with distinct anthers dehiscing vertically, pollen spheric; pistils 1 or 4, usually lacking stipes but sometimes short-stipitate.

Drupes ovoid with rounded sides, 1.5-2.2 mm long and 1.2-1.6 mm broad, uncommonly concave; not keeled; beak erect, median, rarely near upper edge.