Northern Prairie Wildlife Research Center
Western Wetland Flora
Field Office Guide to Plant Species
Potamogeton nodosus Pair.
- Family: Pondweed (Potamogetonaceae)
- Flowering: June-August
- Field Marks: This pondweed has both submersed and floating leaves. The submersed leaves do not clasp the stem and are 1/2-1 1/2 inches wide and are on stalks at least 1 inch long. The elliptic to oblong floating leaves are 2-5 inches long and 1-
- Habitat: Quiet waters of ponds, lakes, streams, and ditches.
- Habit: Partially submersed perennial with spreading rhizomes.
- Stems: Rather stout, branched or unbranched.
- Leaves: Of two kinds: submersed leaves linear-lanceolate, 4-8 inches long, 1/2-1 1/2
inches wide, thin and very weak, with 7-15 veins, with a leaf stalk at least 1 inch long; floating leaves elliptic to oblong, 2-5 inches long, 1-2 inches wide, with 10-20 veins, on stalks up to 10 inches long.
- Flowers: Several crowded into spikes, the spikes up to 2 1/2 inches long, on stout stalks up to 6 inches long.
- Sepals: 4, greenish, 1/8-1/6 inch long.
- Petals: 0.
- Stamens: 4.
- Pistils: 4, each with a superior ovary.
- Fruits: Achenes obovoid, asymmetrical, up to 1/6 inch long, up to 1/8 inch wide, with a short beak at the tip.
- Notes: The achenes are eaten by waterfowl.
Previous Species -- Floating-leaf Pondweed (Potamogeton natans)
Return to Species List -- Group 4
Next Species -- Sago Pondweed (Potamogeton pectinatus)