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Trapa natans L.

Species
ISFS : 423500
Checklist : 1047240

Synthesis

Species description (© Flora Helvetica 2018)

Wasserpflanze mit schwimmender Blattrosette und flutendem oder kriechendem, bis 3 m langem Stängel, dieser mit gegenständigen, fiederig verzweigten Wurzeln. Blätter rhombisch, 2-6 cm lang, vorn grob buchtig gezähnt, lederig, oberseits glänzend, unterseits meist rotbraun, Stiel spindelförmig aufgebläht. Blüten weiss, 4teilig, weniger als 1 cm lang, in den Blattwinkeln, gestielt. Frucht holzig, braun bis schwarz, mit Zacken und Hörnern, 2-3 cm hoch und 2-4 cm breit.

Flowering period (© Flora Helvetica 2018)

8

Habitat and distribution inside Switzerland (© Flora Helvetica 2018)

Stehende, 1-2 m tiefe Gewässer / kollin / Südliches TI, JN

World distribution (© Flora Helvetica 2018)

Eurasiatisch

Ecological indicator (© Landolt & al. 2010)

5v23-44+4.s.2n=36,40,48

Status

IUCN status

 Critically endangered

National Priority

 2 - high national priority

International responsibility

 1 - weak

Conservation

Threats


Bautätigkeit
Wasserverschmutzung (Camping, Bootsmotoren, Einleitungen, Landwirtschaft)
Eutrophierung, Ablagerung von Trübstoffen
Sukzession

Distribution map

Simple

Before threshold year
After threshold year
Before and after threshold year

Advanced

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

Number of observations

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

Habitat and distribution inside Switzerland

Südliches TI, JN

World distribution

Eurasiatisch

Ecology

Life form

Pleustophyte

Habitats

Habitats © Delarze & al. 2015

Character species 1.1.4 - Schwimmblattgesellschaft (Nymphaeion)

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 5v Light Value L 4 Salinity Index --
Reaction Value R 2 Temperature factor T 4+
Nutriments value N 3 Continentality K 4
  • Ecological values legend
    Humidity Value H
    1very dry
    1+dry
    2moderatly dry
    2+moist
    3medium wet
    3+wet
    4very wet
    4+soggy
    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
    1halotolerant
    3halophyle
    Light Value L
    1very shady
    2shady
    3lighted areas
    4luminous
    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)

Water dependency

Rivers 0 - No link
Calm water 2 - Essential habitat
Ground water 0 - No link

Nomenclature

Accepted Name (Checklist 2017)

Trapa natans L.

Vernacular name

Deutscher Name :

Wassernuss

Nom français :

Châtaigne d'eau, Macre flottante

Nome italiano :

Castagna d'acqua

Match with other reference books

Relation Nom Book No
=Trapa natans L.Checklist 2017423500
=Trapa natans L.Flora Helvetica 20011256
=Trapa natans L.Flora Helvetica 20121029
=Trapa natans L.Flora Helvetica 20181029
=Trapa natans L.Index synonymique 1996423500
=Trapa natans L.Landolt 19772124
=Trapa natans L.Landolt 19911738
=Trapa natans L.SISF/ISFS 2423500
=Trapa natans L.Welten & Sutter 19821087
= 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)

Status

Native status

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

Status on national Red List 2016

IUCN status:

 Critically endangered

Critically endangered

Additional information

IUCN criteria: C2a(ii)

Status on regional Red List 2019

Biogregraphic regions Status IUCN criteria
Jura (JU) CRC2a(ii)
Mittelland (MP) CRC2a(ii)
Alpennordflanke (NA) --
Alpensüdflanke (SA) CR(PE)
Östliche Zentralalpen (EA) --
Westliche Zentralalpen (WA) --
  • Legend
    EXExtinct
    RERegionally Extinct
    CR(PE)Critically Endangered, Probably Extinct
    CRCritically Endangered
    ENEndangered
    VUVulnerable
    NTNear Threatened
    LCLeast Concern

National Priority Species List Status

National Priority 2 - high national priority
Need to take action 2 -
International responsibility 1 - weak
Need to monitor populations 2 -

Protection status

International (Bern Convention) Yes
TItotal protection (23.01.2013)
Switzerland total protection
  • Disclaimer
    InfoFlora compiles information on protected species as accurately as possible, taking it from the respective cantonal laws. In some cases, however, it was not possible to use the plant names as listed in the original text, but an interpretation of their taxonomy or nomenclature was necessary. The exact meaning of the categories „completely protected“ and „partially protected“ differs among the cantons.

    InfoFlora cannot guarantee that the information on the protection status is correct and complete. In case of doubts, we recommend to look up the texts of the respective cantonal law.

Conservation

Threats and measures

Bautätigkeit


Vorrang ehemaliger oder potentieller Lebensräume vor Bauprojekten

Wasserverschmutzung (Camping, Bootsmotoren, Einleitungen, Landwirtschaft)


Verstärkung der Wasserschutzmassnahmen
Lenkung der Freizeitaktivitäten

Eutrophierung, Ablagerung von Trübstoffen


Keine Düngung in der Region
grosse Pufferzonen

Sukzession


Teiche künstlich partiell offen halten, sofern diese zu stark zuwachsen

More informations

Conservation fact sheet (in german)E. Bolender et al, 2015: Erfolgskontrolle zur Wiederansiedlung der Wassernuss (Trapa natans) im Raum Wittenberg 1995 bis 1999. Naturschutz im Land Sachsen-Anhalt 52 Jahrgang 2015:63–72E. Guilhodes et al, 2019: La châtaigne d’eau, Trapa natans L. 1753: questions autour d’une expérience de protection en Aveyron et Midi-Pyrénées. Isatis N19