Northern Prairie Wildlife Research Center
Western Wetland Flora
Field Office Guide to Plant Species
Myriophyllum verticillatum L.
- Family: Water-milfoil
- Flowering: June-September
- Field Marks: This milfoil differs from others by having its leaves, flowers, and bracts all arranged in whorls, with the bracts about as long as the flowers and deeply divided but not spiny.
- Habitat: Ponds, lakes, marshes, usually in water.
- Habit: Perennial aquatic herb with rhizomes, usually forming asexual "bulbs" (turions.)
- Stems: Rather stout, mat-forming, branched or unbranched.
- Leaves: All in whorls of 4 or 5, up to 2 inches long, pinnately divided into 8-13 thread-like segments, smooth.
- Flowers: 3-6 in clusters in the axils of the leaves, the male and female flowers usually borne separately but on the same plant, each cluster of flowers subtended by pinnately lobed bracts about as long as the flowers.
- Sepals: 4, green, united below, up to 1/16 inch long.
- Petals: 4, in the male flowers, united below, greenish, up to 1/16 inch long, absent in the female flowers.
- Stamens: 8.
- Pistils: Ovary inferior; stigmas 4.
- Fruits: Spherical, up to 1/8 inch in diameter, smooth.
- Notes: The fruits are eaten by waterfowl.
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