General:
Perennial, aquatic herb from slender rhizomes; stems annual, usually branched, 40-120 cm long, 0.5-2 mm wide.

Leaves:
Tufted at the rhizome nodes, becoming folded or cylindric, 3- (5-) veined, margins entire, (30) 50-150 long, 1-1.5 (2) mm wide.

Flowers:
Inflorescence of stalked spikes of male and female flowers on different plants; female spikes 3-7 per stem, 1-sided, 4 (5) cm long; male spikes 5-6 cm long.

Fruits:
Nutlets, 3-4 mm long, base with 2 downward projecting, hornlike lobes.

Source:  The Illustrated Flora of British Columbia

If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

Illustration Source:  The Illustrated Flora of British Columbia