Elodea densa (Planch.) Casp.

ISFS : 146300
Checklist : 1016370


Species description (© Flora Helvetica 2018)

Ähnlich wie E. canadensis, aber Blätter 2-3 cm lang, zu 4-5 quirlständig, Blüten (selten entwickelt) viel grösser, mit ca. 1 cm langen äusseren Perigonblättern.

Flowering period (© Flora Helvetica 2018)


Habitat and distribution inside Switzerland (© Flora Helvetica 2018)

Stehende und langsam fliessende, warme Gewässer / kollin / Zerstreut, teilweise eingebürgert

World distribution (© Flora Helvetica 2018)

Stammt aus Südamerika

Ecological indicator (© Flora Helvetica 2018)


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

Habitat and distribution inside Switzerland

Zerstreut, teilweise eingebürgert

World distribution

Stammt aus Südamerika


Life form



Habitats © Delarze & al. 2015

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 --
Reaction Value R 3 Temperature factor T 5
Nutriments value N 3 Continentality K 1
  • 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)


Accepted Name (Checklist 2017)

Elodea densa (Planch.) Casp.

Vernacular name

Deutscher Name :

Dichtblättrige Wasserpest

Nom français :

Elodée dense

Nome italiano :

Peste d'acqua maggiore

Match with other reference books

Relation Nom Book No
=Elodea densa (Planch.) Casp.Checklist 2017146300
=Elodea densa (Planch.) Casp.Flora Helvetica 20012386
=Elodea densa (Planch.) Casp.Flora Helvetica 20122378
=Elodea densa (Planch.) Casp.Flora Helvetica 20182378
=Elodea densa (Planch.) Casp.Index synonymique 1996146300
=Elodea densa (Planch.) Casp.Landolt 1977155
=Elodea densa (Planch.) Casp.Landolt 1991146
=Elodea densa (Planch.) Casp.SISF/ISFS 2146300
= 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


IUCN list of endangered species (© Walter & Gillett 1997) : No

Species from the "List of potentially invasive alien species"