Northern Prairie Wildlife Research Center
Western Wetland Flora
Field Office Guide to Plant Species
Spirodela polyrhiza (L.) Schleid.
- Family: Duckweed (Lemnaceae)
- Flowering: June-September
- Field Marks: Spirodela polyrhiza is a duckweed with several roots per frond and with 5 or more distinct veins.
- Habitat: Quiet waters of lakes and ponds, in marshes and slow streams.
- Habit: Floating plant on the surface of water.
- Stems: 0.
- Leaves: Single fronds or fronds cohering in clusters of 2-5, up to 1/3 inch long, up to 1/4 inch wide, green on the upper surface, usually red-purple on the lower surface, with at least 5 distinct veins, smooth.
- Flowers: Rarely formed; if present, the minute male and female flowers borne in pouches known as spathes; male flowers usually 2 per pouch.
- Sepals: 0.
- Petals: 0.
- Stamens: 1.
- Pistils: Ovary superior.
- Fruits: Rarely formed; if present, with a minute wing. Asexual reproductive buds, called turions, are the chief method of reproduction.
- Notes: Like most duckweeds, this one is a source of food for waterfowl.
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