Northern Prairie Wildlife Research Center
Western Wetland Flora
Field Office Guide to Plant Species
Hippuris vulgaris L.
- Family: Mare's-tail (Hippuridaceae)
- Flowering: June-August
- Field Marks: This species is readily distinguished by its whorls of toothless, undivided leaves and single stamen per flower.
- Habitat: In and around lakes, ditches, sloughs, ponds, and streams.
- Habit: Submerged or emersed perennial from slender, creeping rhizomes.
- Stems: Upright, unbranched, up to 2 feet long, smooth.
- Leaves: 6-12 in whorls, the whorls 1/3-1/2 inch apart on the stem, each leaf linear,
sessile, up to 1 1/2 inches long, without teeth or divisions, smooth; submerged leaves
sometimes reduced to short scales.
- Flowers: Solitary in the axils of emersed leaves.
- Sepals: Very tiny, green, united to the ovary.
- Petals: 0.
- Stamens: 1.
- Pistils: Ovary inferior.
- Fruits: Up to 1/8 inch long, nut-like, ellipsoid, hard, not dehiscent, 1-seeded.
- Notes: Leaves that are in the water are usually very soft and weak, resembling those of Elodea, the waterweed, but leaves of Elodea are rarely in whorls of more than 3. The fruits are eaten by waterfowl.
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