Species description (Flora Helvetica 2018)

Ähnlich wie E. canadensis, aber Blätter lineal, 1-2(-3) mm breit, bis 30 mm lang, allmählich zugespitzt, schraubig gedreht und meist stark zurückgebogen, Blüten blasslila, Durchmesser 3-5 mm.

Flowering period (Flora Helvetica 2018)


Habitat and distribution inside Switzerland (Flora Helvetica 2018)

Stehende Gewässer / kollin / M (vom Lac Léman bis zum Bodensee), eingebürgert

World distribution (Flora Helvetica 2018)

Stammt aus Nordamerika

Ecological indicator (Landolt & al. 2010)


Distribution map


Before threshold year
After threshold year
Before and after threshold year


Validated observations
Observations waiting for validation
Occurrences from Atlas Welten & Sutter (1982) and supplements (1984, 1994) without confirmation in the Info Flora database since
Before threshold year
After threshold year
Not native / introduced / subspontaneous / escaped

Number of observations

Below the threshold number of observations
Above or equal the threshold number of observations


Life form



Habitats Delarze & al. 2015

Less strictly linked to a specific habitat 1.1 - Stehende Gewässer
Less strictly linked to a specific habitat 1.1.2 - Laichkrautgesellschaften (Potamion)

bold Dominant species, influencing the appearance of the habitat
Character species Character species
Less strictly linked to a specific habitat Less strictly linked to a specific habitat

Ecological indicator values by Landolt & al. (2010)

Soil factors Climatic factors Salinity tolerance
Humidity Value H 5u Light Value L 3 Salinity Index 1
Reaction Value R 4 Temperature factor T 4+
Nutriments value N 3 Continentality K 2
  • Ecological values legend
    Humidity Value H
    1very dry
    2moderatly dry
    3medium wet
    4very wet
    5submerged or underwater
    fplants living in running water
    umostly submerged plants
    vpartly submerged, partly floating plants
    whumidity moderately variable (± scale of 1-2)
    w+highly variable humidity (scale exceeding ± 2)
    Reaction Value R
    1Very acid (pH 2.5-5.5)
    2acid (pH 3.5-6.5)
    3lightly acid to neutral (pH 4.5-7.5)
    4neutral to basic (pH 5.5-8.5)
    5basic (pH 6-5 -> 8.5
    Nutriments value N
    1very low in nutrients
    2low in nutriments
    3medium-poor to medium-rich in nutrients
    4rich in nutriments
    5very rich in nutriments
    Salinity tolerance
    Light Value L
    1very shady
    3lighted areas
    5highly luminous
    Temperature factor T
    1alpine to nival stages (from the treeline to the snowline)
    1+suprasubalpine and upper subalpine levels (pine and larch forests)
    2subalpine level (coniferous forests without beeches up to the upper limit of spruces)
    2+lower subalpine and upper mountain stages
    3mountain level (beech and silver fir forests, in the central Alps Scots pine forests)
    3+lower mountain and upper hill levels
    4hill level (mixed deciduous oak forests)
    4+hot places, hill level
    5very hot places, hill level (only in the hottest places, typical of southern Europe)
    Continentality K
    1Atlantic (high air humidity, very low temperature variations, mild winters)
    2Sub-Atlantic (high air humidity, low temperature variations, relatively mild winters)
    3sub-Atlantic to subcontinental (average air humidity, moderately variable temperature, slightly low winter temperatures)
    4subcontinental (low air humidity, large temperature variations, rather cold winters)
    5continental (very low air humidity, very large temperature variations, cold winters)


Vernacular name

Deutscher Name:
Nuttalls Wasserpest
Nom français:
Elodée de Nuttall
Nome italiano:
Peste d'acqua di Nuttall

Match with other reference books

Relation Nom Book No
=Elodea nuttallii (Planch.) H. St. JohnChecklist 2017146400
=Elodea nuttallii (Planch.) H. St. JohnFlora Helvetica 20012387
=Elodea nuttallii (Planch.) H. St. JohnFlora Helvetica 20122379
=Elodea nuttallii (Planch.) H. St. JohnFlora Helvetica 20182379
=Elodea nuttallii (Planch.) H. St. JohnIndex synonymique 1996146400
=Elodea nuttallii (Planch.) H. St. JohnLandolt 1977156
=Elodea nuttallii (Planch.) H. St. JohnLandolt 1991147
=Elodea nuttallii (Planch.) H. St. JohnSISF/ISFS 2146400

= The taxon corresponds to the accepted taxon (Checklist 2017)
< The taxon is included in the accepted taxon (Checklist 2017)
> The taxon includes (among others) also the accepted taxon (Checklist 2017)


Native status   -  -

Species from the "Black List" Neophyte- fact sheet


Images and descriptions (© Fritz H. Schweingruber & Hugo Berger)

text alt Stems, 100x
text alt Stems 400x

Summary of stem anatomy (German)

Umriss rund oder oval. Grosse runde oder ovale Intercellularen. Epidermiszellen aussen verholzt.


Culm-diameter 1-2 mm, center full, radius of culm in relation to wall thickness 1:1. With cortex/central cylinder separation. Endodermis present. Epidermis thin-, peripheral thicker-walled (lignified). Chlorenchyma present, continuous peripheral belt with unlignified round cells (like a large cortex). Chlorenchyma present, continuous peripheral belt with unlignified round cells (like a large cortex). Vascular bundles concentric, phloem in the center. Vessels in vascular bundles around the phloem not to recognize in normal light. Cavities (intercellulars) between parenchyma cells round, oval or radial.