General:
Perennial aquatic or semiterrestrial from a rhizome, stems up to 25 cm tall.

Leaves:
Emergent leaves opposite or in whorls of 3, 1-8 mm long, linear or lanceolate in outline, entire or pinnate with 1-3 pairs of segments; submersed leaves in whorls of 3, pinnate, broadly egg-shaped in outline, with 2-4 (7) alternate segments on each side; winter buds 3-7 mm long, threadlike, formed in the leaf axils.

Flowers:
Male and female flowers developed on separate plants (plants dioecious) in the axils of the floral bracts; floral bracts similar to the leaves, usually entire, or with a few stubby segments on each side; male flowers with soon deciduous white petals about 3 mm long; stamens 8, deciduous; female flowers inconspicuous, greenish, with four feather-like stigmas.

Fruits:
Were not observed in BC.

Notes:
Most populations of this species in British Columbia have only female plants; male populations are known from the lower Fraser River valley.

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.