General: Perennial, aquatic herb from strong rhizomes; stems mostly unbranched, up to 200 cm long.
Leaves: Submersed leaves widely lanceolate, 8-20 cm long, 2-7 cm wide, with 27 to 50 veins, tapering into distinct, short stalks greater than 0.5 cm long, folded and curved backwards, strongly sickle-shaped, the tips pointed, the stipules 3-10 cm long, thin, persistent; floating leaves egg-shaped, 5-10 cm long, 2-4 cm wide, leathery, the stalks long, thick, the tips rounded, tapered at the bases.
Flowers: Inflorescence spikelike, the spikes 4-8 cm long, with 6 to 10 whorls of flowers, the stalks thick.
Fruits: Achenes, widely egg-shaped or almost globe-shaped, 5-6.7 mm long, 4.5-5.5 mm wide, the beaks widely triangular, the keels broad.
Notes: Stem anatomical characters Interlacunar bundles strongly developed throughout the stem aerenchyma, subepidermal bundles absent, pseudohypodermis 1 or 2 cells thick, endodermis of O-cells.
Lakes and ponds in the lowland and montane zones; frequent in SW BC, infrequent E of the Coast-Cascade Mountains south of 55 degrees N; disjunct E from MB to NF and S to ME, PA, NC, GA, AL, MS, LA, OK, CO, UT, NV and CA.
The table below shows the species-specific information calculated from original data (BEC database) provided by the BC Ministry of Forests and Range. (Updated August, 2013)
