Northern Prairie Wildlife Research Center
Western Wetland Flora
Field Office Guide to Plant Species
Potamogeton pusillus L.
- Family: Pondweed (Potamogetonaceae)
- Flowering: July-September
- Field Marks: This pondweed only has submersed leaves and not floating ones. Submersed
leaves are only 1/12 inch wide but have 3 distinct veins. The slender stems are usually thread-like and much branched.
- Habitat: Quiet waters of lakes, ponds, and streams.
- Habit: Submersed perennial with slender rhizomes.
- Stems: Very slender, often thread-like, much branched.
- Leaves: All submersed, about 1/12 inch wide, with 3 conspicuous veins, smooth, with 2
minute glands where leaf is attached to the stem.
- Flowers: Several in whorls crowded into spikes, the spikes up to 3/4 inch long, borne on smooth stalks up to 2 1/2 inches long.
- Sepals: 4, green, 1/20-1/10 inch long.
- Petals: 0.
- Stamens: 4.
- Pistils: 4, each with a superior ovary.
- Fruits: Achenes obovoid, asymmetrical, up to 1/8 inch long, with a minute beak at the tip.
- Notes: This species is variable in the number of flowering and fruiting heads per plant and in the length of the stalks that bear the heads. The achenes are eaten by waterfowl.
Previous Species -- White-stem Pondweed (Potamogeton praelongus)
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Next Species -- Richardson Pondweed (Potamogeton richardsonii)