General:
Perennial, aquatic herb from fine, tufted roots; stems up to 130 cm long, strongly compressed, flattened, branched.

Leaves:
All submersed, linear, the sides parallel, stiff, olive green, 10-20 cm long, 0.2-0.5 cm wide, unstalked, usually with 7 to 15 veins, attached at the nodes, tapering to pointed tips, the stipules 1.5-3.5 cm long, the margins overlapping, straight, smooth.

Flowers:
Inflorescence spikelike, the spikes 1.5-3 cm long, with 5 to 9 whorls of flowers, the stalks thin.

Fruits:
Achenes, egg-shaped, 4-5 mm long, 3-3.5 mm wide, the beaks conspicuous, the keels winged.

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

Flower Colour:
Green

Blooming Period:
Mid Summer

Fruit/Seed characteristics:
Colour: Green
Present from Summer to Fall

Source:  The USDA

Synonyms and Alternate Names:
Potamogeton compressus auct. non L.
Potamogeton zosterifolius subsp. zosteriformis (Fernald) HultΘn