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| Elodea bifoliata St. John | Species Image Gallery (opens in a new window) |
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| TAXONOMY | |||||||||
| Family: | Hydrocharitaceae | ||||||||
| Genus: | Elodea | ||||||||
| Species Synonyms: | Elodea longivaginata St. John Elodea nevadensis (Planch.) St. John |
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| Common Names: | twoleaf waterweed long-sheathed waterweed |
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| DISTRIBUTION | |||||||||
| Canada: | southern Alberta – southwestern Saskatchewan | ||||||||
| Saskatchewan: | southwestern Saskatchewan; Cypress Hills – Buffalo Pound Lake | ||||||||
| Ecoregion: | Cypress Upland, Mixed Grassland, Moist Mixed Grassland | ||||||||
| HABITAT | |||||||||
| Saskatchewan: | floating, shallow-water aquatic in lakes, ponds, and sloughs | ||||||||
| Associated Species: | pondweed species | ||||||||
| RARITY STATUS | |||||||||
| Provincial
Status According to Harms (2003): |
Threatened |
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| Nature Conservancy Status: | G4G5 N2S2 |
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| Saskatchewan
Species at Risk Status: |
None |
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| COSEWIC Status: | None |
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| Twoleaf waterweed is threatened in Saskatchewan because it is rare and somewhat regionally restricted. Local population sizes vary and possible threats have been identified. | |||||||||
| SPECIES DESCRIPTION | |||||||||
| Height: | fibrous | ||||||||
| Stems: | perennial, slender, 30 – 100 cm long, simple or sparingly branched | ||||||||
| Leaves: | opposite, 6 – 12 mm long, 0.5 – 1.5 mm wide, linear to narrowly elliptic, flat, terminal leaves not especially crowded, limp | ||||||||
| Inflorescence: | solitary, sessile, male and female inflorescences on different plants; male flowered inflorescence bract 2 – 15 cm long, inflated near the tip, cylindrical, tip with two teeth; female flowered inflorescence bract 3 – 7 cm long, linear, tip with two teeth | ||||||||
| Flowers: | unisexual, usually projected to surface of water by elongate hypanthium, sessile, petals white; male flowers on thread-like stalks up to 30 cm long, stamens 7 – 9, inner 3 filaments fused forming a column, pollen in monads; female flowers with a unilocular ovary, strap-shaped sterile stamens 3, styles 3, hypanthium elongate and stalk-like up to 30 cm long | ||||||||
| Fruits: | capsule 10 mm long, 3 mm wide, ovoid to ellipsoid, opening irregularly; seeds several, ellipsoid, long hairy | ||||||||
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