General: Perennial, aquatic herb from strong rhizomes; stems up to 200 cm long, unbranched.
Leaves: Submersed leaves reduced to narrow, firm, dark green cylindrical stalks without blades, growing from the main stem, 10-20 cm long, the stipules 4-9 cm long, fibrous; floating leaves egg-shaped, 3-10 cm long, 2.5-6 cm wide, the larger ones with (18) 20 to 35 veins, leathery, long-stalked, the tips rounded, notched at the bases.
Flowers: Inflorescence spikelike, the spikes with 6 to10 whorls of flowers, the stalks thick.
Fruits: Achenes, broadly egg-shaped, 3.5-5 mm long, 2.5-3.5 mm wide, the beaks cylindrical, the keels obscure, developed in the upper half of achenes.
Notes: Stem anatomical characters Interlacunar bundles present throughout the stem aerenchyma in several circles, subepidermal bundles present, pseudohypodermis 1-cell thick, endodermis of U-cells.
Lakes and ponds from the lowland and steppe to subalpine zones; common throughout BC; circumpolar, N to AK, YT and NT, E to NF and S to ME, MA, PA, NC, OH, IN, IL, IA, OK, NM, UT, AZ and CA; Eurasia.
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)
