Northern Prairie Wildlife Research Center
Western Wetland Flora
Field Office Guide to Plant Species
Potamogeton richardsonii (Ar. Benn.) Rydb.
- Family: Pondweed (Potamogetonaceae)
- Flowering: June-August
- Field Marks: This species is distinguished readily by its lanceolate leaves that are broadly rounded at the base and clasp the stem, its achenes that are never longer than 1/6 inch, and the stems that are not zigzag.
- Habitat: Shallow water of lakes and streams.
- Habit: Submersed perennial herb with slender rhizomes.
- Stems: Submersed, branched, rather stout, up to 2 feet long, not zigzag.
- Leaves: Alternate, simple, all submersed, lanceolate to broadly lanceolate, up to 4 inches long, up to 1 inch wide, pointed at the tip, broadly rounded at the base and clasping the
stem, smooth; stipules 1/2-1 inch long, shredded into white fibers.
- Flowers: Crowded together into spikes, each spike up to 2 inches long on stout stalks up to 6 inches long.
- Sepals: 4, green, free from each other, up to 1/6 inch long.
- Petals: O.
- Stamens: 4.
- Pistils: 4, each with a superior ovary.
- Fruits: Achenes obovoid, up to 1/6 inch long, with a tiny erect beak at the tip.
- Notes: The achenes are eaten by waterfowl.
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