Taxonomy
Family: Potamogetonaceae
Habitat
Streams, lakes, ditches, often in alkaline water.
Associates
Distribution
Widespread, nearly cosmopolitan.
Morphology
Perennial aquatic with floating leaves; stems 1-2 m long, simple or with a few branches. Submersed leaves thin, narrowly lanceolate to linear, to 30 cm long and 2.5 cm wide, 7-15 veins, acute, gradually tapering to a petiole 2-12 cm long; floating leaves elliptic, to 13 cm long and 4 cm wide, more or less acute; petioles to 20 cm; stipules axillary, free, to 10 cm long, attenuate to obtuse; peduncles to 12 cm long, stout, often thicker than the stem; spikes cylindric, dense, to 5 cm. Fruits somewhat obovoid, to 4 mm, with a sharp, narrow, often tuberculate dorsal keel and occasionally with 2 low ridges on the sides.
Notes
Flowers July.
Wetland indicator: Obligate
One of the more common pondweeds.
References
Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. Second Ed.
The New York Botanical Garden. Bronx, NY
Swink, F. and G.
Wilhelm. 1994. Plants of the Chicago Region.
Indiana Academy of Science. The Morton Arboretum. Lisle, Illinois.
Michael Hough © 2009 |