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

General:
Perennial aquatic from a short rhizome; stems stout, olive green, 2-3 mm wide, 60-120 cm long.

Leaves:
In whorls of 4 to 6, with some additional alternate leaves scattered outside the whorls; emersed leaves linear, the lower ones pinnately dissected into capillary divisions, the upper ones deeply sharp-toothed or entire; winter buds absent.

Flowers:
Perfect or the lower ones female and upper ones male; bracteoles minute, not more than 0.7 mm long; petals white, 1-2 mm long; stamens 4.

Fruits:
Mericarps, 4, laterally compressed, 1.5-2 mm long, with smooth dorsal ridges.