E-Flora BC: Electronic Atlas of the Flora of British Columbia

General:
Aquatic annual herb from fibrous roots; stems 3-20 cm tall.

Leaves:
All basal, tufted, linear, 5-35 cm long, 1-4 mm thick, the tips abruptly to gradually pointed; sheaths 3-10 cm long, translucent.

Flowers:
Inflorescence of 3 types either male/female flowers on spikes, male flowers mainly on top of spikes; or female mainly at base of spikes and solitary in submersed leaf axils; female/male flowers with 1 perianth part, 2-3 mm long, 1 stamen and 1 ovary; male flowers with 1 perianth part, 2-3 mm long, 1 stamen; female flowers lacking a perianth part and with 1 ovary; styles short or lacking in spike flowers or 5-25 cm long and threadlike in axillary flowers.

Fruits:
Nutlets, 2-5 mm long, with 25 to 30 ribs and several wings, the axillary, basal ones beaked at the tips.