American Water-lily - Nymphaea odorata
Fragrant Water-lily, American White Water-lily
State Rank Reason (see State Rank above)
Nymphaea odorata is exotic in Montana (FNA 1997; Booth and Wright 1966), but is not listed as a noxious weed in Montana. Plants in Montana are subspecies odorata (FNA 1997; Lesica 2012). It was introduced from the eastern United States for its ornamental appeal (FNA 1997; Lesica 2012). In some states and provinces Fragrant Water-lily is considered invasive. A conservation status rank is not applicable (SNA) because exotic plants are not a suitable target for conservation activities.
PLANTS: Aquatic perennials with floating leaves and floating, showy flowers (Lesica 2012). Rhizomes are 2-3 cm in diameter, long, branched, creeping, and covered with short, black hairs (DiTomaso and Healy 2003).
LEAVES: Large, floating, nearly orbicular, and 8-20 cm long (Lesica 2012). Leaves are green above and green to purple below (FNA 1997). Margins are entire (smooth) and bases are cordate-shaped, like the top of a heart (FNA 1997). Petioles are long and attached to a rhizome.
INFLORESCENCE: Singular flowers have at least 17 white, showy petals, 4 green or reddened sepals of at least 3 cm long, and float with long peduncles (flower stems) (FNA 1997; Lesica 2012).
Flowering occurs from spring to summer, or into early fall for more southern populations (DiTomaso and Healy 2003).
In Montana three genera represent the “water-lily family”: Brasenia (water shield), Nuphar (pond-lily), and Nymphaea (water-lily).
Brasenia spp. have round to elliptical floating leaves with no basal sinus or split in the leaf.
Nuphar spp. have heart-shaped floating leaves (appear split), yellowish sepals, and inconspicuous petals.
Nymphaea spp. have heart-shaped floating leaves (appear split), 4 green sepals, and numerous white petals. In Montana Nymphaea odorata and N. leibergii differ in their fragrance, sepal length, and number of petals. Nymphaea odorata has fragrant flowers (Hitchcock et al. 1964), at least 17 white petals, and sepals of at least 3 cm long (Lesica 2012). Nymphaea leibergii lacks fragrant flowers (Hitchcock et al. 1964), has 7 to 15 petals, and sepals of 3 or less cm long (Lesica 2012).
In Montana our plants are Nymphaea odorata subspecies odorata.
Introduced from the eastern United States, Fragrant Water-lily is found in all western states except Wyoming (DiTomaso and Healy 2003). Two subspecies (tuberosa and odorata) are recognized in the United States, and where populations overlap intermediate forms develop (FNA 1997).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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(Observations spanning multiple months or years are excluded from time charts)
Acidic to alkaline lakes and ponds in valleys (DiTomaso and Healy 2003; Lesica 2012).
Ecological Systems Associated with this Species
Fragrant Water-lily has rhizomes that can tolerate some desiccation (DiTomaso and Healy 2003). Plants can also become abundant, shading out native plants,and impairing recreation.
- Additional ReferencesLegend: View Online Publication
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- Booth, W. E. and J. C. Wright. 1966. Flora of Montana-Part II: dicotyledons. Montana State University, Bozeman, MT. 305 pp.
- DiTomaso, J.M. and E.A. Healy. 2003. Aquatic and riparian weeds of the West. Regents of University of California, Division of Agriculture and Natural Resources, Publication 3421.
- FNA - Flora of North America Editorial Committee. 1997. Flora of North America, Magnoliophyta: Magnoliidae and Hamamelidae, Vol. 3. Oxford University Press. Inc., New York, New York.
- Hitchcock, C. L., A. Cronquist, M. Ownbey, and J. W. Thompson. 1964. Vascular Plants of the Pacific Northwest. Part 2: Salicaceae to Saxifragaceae. University of Washington Press, Seattle. 597 pp.
- Lesica, P., M. T. Lavin, and P. F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.