Aquatic and Wetland Vascular Plants of the Northern Great Plains
55. Potamogetonaceae, the Pondweed Family
1. Potamogeton L. -- Pondweed13. 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).
Previous Section -- Potamogeton nodosus Poir. -- Longleaf pondweed
Return to Family -- Potamogetonaceae - The Pondweed Family
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