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

13. Potamogeton pectinatus L. -- Sago pondweed

Stems terete, ca. 1 mm thick, or the main stem stouter on deep water forms, sparingly branched at the base, becoming freely dichotomously branched above, 3-10 dm long. Leaves all submersed, filiform to narrowly linear, 3-12 cm long, usually 0.2-1 mm wide, 1- to 3-nerved, acute, sometimes wider with obtuse tips early in the growing season or on plants from running water; stipules adnate to the base of the leaf blade for 1-3 cm, forming a sheath about as wide as the stem, occasionally wider on the main stem, especially in deep water forms. Spikes elongate, 1-5 cm long, with 2-5(7) unevenly spaced floral whorls; peduncles lax, filiform, to 15 cm long. Fruits yellowish to tawny, drying brown, obliquely obovoid, 2.7-4 mm long, rounded on the back, apiculate due to the style beak which is usually 0.3-0.5 mm long. Jun--Sep. Shallow to rather deep, fresh to subsaline water of lakes, ponds, marshes, ditches, rivers and streams; common and often abundant; (Nearly cosmopolitan).
GIF- Species Photo/Drawing
Potamogeton pectinatus, upper portion with fruiting spike.
GIF- Distribution Map

Map key

Previous Section -- Potamogeton nodosus Poir. -- Longleaf pondweed
Return to Family -- Potamogetonaceae - The Pondweed Family
Next Section -- Potamogeton praelongus Wulf. -- Whitestem pondweed

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Webmaster
Page Last Modified: Saturday, 02-Feb-2013 06:45:58 EST
Sioux Falls, SD [sdww54]