General: Perennial, aquatic herb from long rhizomes; stems erect, emersed (occasionally floating), 30-40 cm tall.
Leaves: Alternate, erect, emersed (occasionally floating), keeled and triangular in cross-section, linear with sheathing bases, 70-85 (100) cm long, 2-12 mm wide.
Flowers: Inflorescence simple, of 2 to 4 female heads below and 2 to 5 (8) male heads above, the heads globe-shaped, the female heads 1-2 cm wide, at least some borne above the leaf axils and subtended by conspicuous leaflike bracts; perianth segments 6, scalelike, attached near the top of the flower stalk; stigma 1; anthers about 1 mm long, 0.5 mm wide.
Fruits: Achenes, 2-4.5 mm long, constricted at the middle, achenes greenish at base prior to drying, beaked, the beaks 3-4 mm long, straight or slightly curved, the stalks 1-1.5 mm long; seeds 1.
Ponds, ditches and lakeshores in the lowland, steppe and montane zones; common throughout BC; circumpolar, N to AK, YT and NT, E to NF and S to ME, MA, NY, PA, VA, IN, MN, SD, NM, AZ and CA; Greenland, Europe.
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)
