Kentucky Nature Preserves Rare Plants

Kentucky State Nature Preserves Commission

Western Waterweed
Elodea nuttallii
Family: Hydrocharitaceae

Protection Status:
State Status:  T
USFWS Status: {null}

Global Rank: G5
State Rank: S2?

Ponds, cool waters of spring branches, stream margins, sloughs.

Species Description:
Aquatic perennial herb.

Flowering Period: Early July to late September.

Additional Information at NatureServe

Diagnostic Characteristics:
Aquatic plant occurring in quiet waters (ponds) with cauline leaves that are slender (ca 1.3 mm wide), flaccid, sharply serrulate and 1-nerved. They are arranged in whorls of 3 or are opposite and the upper ones are not closely over-lapping. The staminate spathe is smaller(2-4 mm) and sessile and then separating from plant and floating. There are 9 stamens. It is interesting to note that this plant has become invasive in some parts of Europe; it has spread to become locally weedy in eutrophic waters.

Avoid changes in moisture/hydrologic conditions at the site. Changes could result from overstory removal, stream/wetland alteration or impacts due to erosion. Exotec pest plants are a threat and should be removed.

Global Range:

Known Kentucky Occurrences:

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Data last updated: Wednesday, May 28, 2014
Kentucky State Nature Preserves Commission
801 Teton Trail
Frankfort,KY 40601
Phone: (502) 573-2886
Fax: (502) 573-2355
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