USGS - science for a changing world

Northern Prairie Wildlife Research Center

  Home About NPWRC Our Science Staff Employment Contacts Common Questions About the Site

Aquatic and Wetland Vascular Plants of the Northern Great Plains

55. Potamogetonaceae, the Pondweed Family

1. Potamogeton L. -- Pondweed

10. Potamogeton illinoensis Morong -- Illinois pondweed


Stems subterete, (1)1.5-5 mm thick, simple or branched, to 2 m long. Submersed leaves elliptic or oblong-elliptic to lanceolate or linear-lanceolate, sometimes somewhat arcuate, 5-20 cm long, (1)1.5-4 cm wide, mostly 9- to 17(19)-nerved, acute to mucronate, tapered to the subsessile or petioled base, the petioles up to 2-4 cm long. Floating leaves often lacking, oblong-elliptic or ovate-elliptic to broadly elliptic, 4-14(19) cm long, 2-7 cm wide, 13- to 29-nerved, obtuse to bluntly mucronate at the tip, rounded to cuneate at the base; petioles 2-9 cm long, shorter than the blades; stipules free, persistent, mostly 2-8 cm long. Spikes dense, cylindric, 2-6 cm long; peduncles usually thicker than the stem, 4-20(30) cm long. Fruits olive-green or gray-green, obliquely obovoid, 2.7-3.5 mm long, dorsal and lateral keels prominent. Jun--Sep. Shallow to fairly deep water of sandy lakes and ponds; common in the NE Sandhills, otherwise widely scattered in SD; (N.S. to Ont. and B.C. s to FL, KS, CA and into Mex.).

See discussion under the preceding.


GIF- Distribution Map

Map key


Previous Section -- Potamogeton gramineus L. -- Variable pondweed
Return to Family -- Potamogetonaceae - The Pondweed Family
Next Section -- Potamogeton natans L. -- Floatingleaf pondweed

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://www.npwrc.usgs.gov/resource/plants/vascplnt/species/pill.htm
Page Contact Information: Webmaster
Page Last Modified: Saturday, 02-Feb-2013 06:45:30 EST
Sioux Falls, SD [sdww55]