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

General:
Aquatic, either submersed or semiterrestrial perennial; stems rooting in mud, freely branched or becoming much elongated when growing in water.

Leaves:
In whorls of 3 to 5 or subverticillate or commonly scattered, to about 3 cm long, the submersed leaves with about 5 or more short or somewhat elongate remote capillary divisions; emersed leaves linear to oblanceolate, comb-like or sharply toothed, to 2 cm long; winter buds absent.

Flowers:
Perfect or unisexual in the axils of the emersed leaves; bracteoles bluntly triangular, about 1 mm long; petals purplish, 1.5-2 mm long, rounded above, with a short claw; stamens 4, anthers about 1 mm long.

Fruits:
Mericarps, 4, pale, 1.3-1.8 mm long, with flat sides and tiny warts on the dorsal ridges.

Notes:
This eastern North American species has been identified based on a fruiting specimen collected by Frank Lomer in Port Coquitlam in 1996. There is a sterile specimen in the Royal British Columbia Museum, collected by J. K. Henry in 1918, that most probably belongs to this species.