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WendySchollInvasionEcology
SwollenBladderwort
Scientificname:Order/Family/Genus/Species
Scrophulariales/Lentibulariaceae/UtriculariaL./UltriculariainflatalU.infiata
waiter
CommonNames:
SwollenBladderwort,FloatingBladderwort,LargeFloatingBladderwort,Inflated
Biadderwort.
1
Overview:
SwollenBladderwortisaknowninvasivespeciesinthestateofWashington.
IntroducedtoWesternWashingtonintheearly1980’stheplantisnowfoundinat
least5counties.Atthistimeit’smethodofintroductionisunknown.Utricularia
inflata’scloseresemblancetoothernativebladderwortsisproblematicinthatit
presentsthepossibilitythatwemayhavealargerinvasivepopulationthanwe
currentlyrealize.Abeautifulandfascinatingspecies,itisknowntobeendangeredin
someofitshomeranges.That,however,doesnotpreventitfromposingasignificant
threattosomeofourownnativepopulationsoffloraandfaunainadditionto
possiblyseriousfinancialcostsshoulditslocalrangeincrease.WhileU.infiatais,as
farasweknow,limitedtoahandfuloflocationsinWesternWashingtonatthistime,
thereisadisturbinglackofanyefforttoeradicatethepopulationwhileitremains
small.
Keyfeatures:
BasicfeaturesforUtriculariainflataare:
A.Lacyunderwaterfoliagewithseed-likebladders
B.Yellowsnapdragon-likeflowers
C.Spoke-likestructuresupportingtheflowerstalk
Utriculariainflataisdifferentiatedfromotherbladderworts,especiallyUtricularia
radiata,basedonthesekeyfeatures;Thelateralfoliarunits(leaves),floats,vernation
(thearrangementofyoungleavesinabud)ofthebranchtips,theinflorescence
bracts,flowers,pedunclelengths,orientationofthefruitingpedicel,character
correlation(obtainedbyplottingflowernumberagainstpedunclelength),and
distribution(Reinertetal.1962).(FIG1.)
2
.I4VI,49
r1
-
1
/.-7i4-
-“I)ij
FIG.1;KeydescribingdistinguishingfeaturesofUtriculariainflata;Courtesyof
TheAmericanJournalofBotany.
---
I
3
LifeHistoryandbasicecology:
SwollenBladderwortisafree-floatingperennialherb;rootless,carnivorous,and
aquatic,ituses“seeds”orbladderstocaptureprey.Thestemandflowersare
supportedbyawheelorspoke-likestructurewithlacy,finelydividedandhaired
underwaterfoliage.Thestemcanvaryfromsixinchestotwometerslongandwhile
usuallyemergent,canbeeitherpartlysupportedbyexposedsediment,submersedor
floating. 16Theemergentflowersareyellowandsnap-dragon-likeinappearancewith
alower,banner-shapedpetal.Theyoccuringroupsof3to14ontheupright
stems.14
InswollenBladderworttheseedstalkcanbeupto35mmlong.’ 4Theplant
hasnotrueleaves.Althoughoftenreferredtoasleaves,thatfunctionalpurposeis
servedbythebladder-bearing,chiorophyllouslaterals.Asshootsterminatingin
tubersdooriginatefromthesestructuresundercertainconditions 2,Reinert(1962)felt
thattheyaremorelikelystemstructures(Remertetal.1962;FarooqCtal.1966).The
floatcanappeardenseandbushyunderwaterandhasanywherefrom4to10
spokes 5.Thespokesthemselvesvaryfrom4to9cm.’ 4andareslenderatthebase,
wideninginthemiddleandthentaperingagainattheterminalend.
U.injiatareproducesfromseeds,fragments,tubers,andsmallcoiledwinterbuds,
alsocalledturions 2Turionsaretightlypacked,ball-shapedgroupsofconcave
leavescoveredinprotectivemucus.Theseareheavywithstarchesandsinktothe
bottomofthewatercolumnwheretheyremaindormantinthesedimentforthe
winter’ 0.ThetubersofUinflataareproducedwhentheplantbecomesstrandedon
sedimentsduetolowwater.Theplantsendsoutthin,thread-likeshootsthat
terminateintiny,starch-filledtubers.Whilethethinshootscanbeproducedduring
periodswhenthewaterlevelsdropandthewaterbecomesstagnant,thetubers
themselvesareonlyproducedwhentheplantactuallybecomesembeddedinthe
benthicdeposits(Reinertetal.1962).Reinertalsostatesinhis1962paperthatwhile
theyneversawthesetubersresultingerminationinthefieldtheydidsoeasilywhen
submersedinwaterinthelaboratory.Relatedtoit’sabilitytoreproducefrom
fragments,ithasalsobeenobservedthatattheendofthefruitingseasontheolder
‘6lnternetPublication/OnlineDocument;www.aquariumarticles.com2
InternetPublication/OnlineDocument;WashingtonStateDepartmentofEcology5lnternetPublication/OnlineDocument;MassachusettsDepartmentofConservationandRecreation.‘4lnternetPublication/OnlineDocument;WashingtonStateDepartmentofEcology‘°
InternetPublication/OnlineDocument;BotanicalSocietyofAmerica.4
partsoftheplantappeartodecayandthebranchtipsseparate,remainingdormant
untilthenextgrowingseason.
SwollenBladderwortis,asstatedearlier,carnivorousandobtainsnutrientsvia
photosynthesis,absorbingnutrientsfromthewatercolumnandbyconsumingtiny
invertebratesandminutefishthatitcapturesinitsbladders. 5Thebladdersare,in
fact,trapsanduseavacuum4ikesuctiontopullpreyinsideafterthepreyhas
triggeredthebladders“trapdoor”. 2Theanimalsareattractedtothebladdersbyway
ofasweet“scent” 5ormucusandopenthetrapdoorsbycomingintocontactwith
triggerhairs.Enzymesandbacteriadigesttheanimalonceithasdiedinsidethe
bladder.ThebladdersofcarnivorousUtriculariaspeciesare10%-50%ofthetotal
biomassoftheplant(Adamec,2006).Whenmaturethebladdersareapproximately3
mm.long(Reinertetal.1962).
2InternetPublication/OnlineDocument;WashingtonStateDepartmentofEcologyInternetPublication/OnlineDocument.MassachusettsDepartmentofConservationand
Recreation
FIG.2Close-upofUtriculariainflatabladdershowingtriggerhairs.Courtesyof
TheNatureConservancy.
5
Duetotheirabilitytocaptureliveprey,theyareabletoflourishinbotholigotrophic
aswellaseutrophiclakes 5.This,combinedwiththeirtoleranceforawiderangeof
waterchemistryconditions,givesthemacompetitiveedgeovermanynativeplants.
Optimalconditionsforaquaticbladderwortspeciesarewarm,shallow,
oligotrophicwatersthatareoxygendeficient. 5Aciditytolerancescanvarywithsome
speciesdoingwellinmoreacidicwatersandothersrequiringahighpH.(Diteetal.
2006).Itprefersslowmovingandstillwatersandcancreatedensematsthatshade
outnativevegetation.It’swiderangeoftolerancesandabilitytoutilizeresources
givesitadvantagesintheunlikeliestoflocations.Inatleastonedocumentedinstance
itwaslocatedinanunnameddrainagepondbesideahighwayinThurston
InternetPublication/OnlineDocument;MassachusettsDepartmentofConservationandRecreation.
www.BestC
;iII7’
FIG.3Utriculariainflatastemsandbladders
6
County,Washington,notasitelikelyvisitedbyrecreationalboatersoraquaria
enthusiasts.
Bladderwortsintheirnativerangesprovideimportantfood,habitat,andprotection
forfishandaquaticinvertebrates.Waterfowlandanotherhighlyinvasivespecies,the
muskrat,alsoconsumethem.Althoughitflowersduringthewinterinitsnative
rangeitflowersmuchlater,fromJunetoJuly,inWashington. 2Whennotinflower
itisdifficulttodistinguishfromournativebladderwortsbutwheninflower,is
distinguishedbyitsspoke-likefloat.AccordingtotheWashingtonStateDepartment
ofEcology,swollenbladderwort,whennotinflower,maybeeasilyconfusedfor
other,smallernativeblaclderwortsaswellaswatermilfoils(Myriophyllumspp.)and
Whitewaterbuttercup(Ranunculusaquatiis).
OriginandDistribution:
Thereseemstobesomeconfusionoverthetotalnumberofbladderwortspecies,
withReinert(1962)listing300andtheAmericanBotanicalSocietylisting220.
Publishedinformationindicatesthatapproximately30areaquatic.Inadditionthere
islittleconsensusonthenativedistributionwiththegeneralobservationbeingthe
easterncoastalplainsoftheUnitedStates.Bladderwortshavedispersedacrossthe
globeandarenativetonearlyallecosystemsfromAustraliatoAlaska(Reinertetal.
1962).Approximately20speciesareendemictotheUnitedStatesandUinfiatais
nowknowntobepresentinAlabama,Arkansas,Delaware,Florida,Georgia,
Kentucky,Louisiana,Maryland,Mississippi,NewJersey,NorthCarolina,
Oklahoma,Pennsylvania,SouthCarolina,Tennessee,Texas,Virginiaand
Washington.
NativedistributionisreportedasoccurringontheoutercoastalplainfromTexas
andAlabamatoDelaware(Reinertetal.1962;Urbanetal.2006).Ithasbeen
reportedthatUinflatahadspreadasfarnorthasNewYorkandMassachusettsby
theearly1990’s(Urbanetal.2006;Mitchelletal.1994).Althoughtheplantisnative
towarmersouthernwatersithasbeenshowntobecapableofsurvivalincolder
climatesandisabletosurvivethewinterinfrozenlakes.
2InternetPublication/OnlineDocument;WashingtonStateDepartmentofEcologyInternetPublication/OnlineDocument;MassachusettsDepartmentofConservationand
Recreation.7
%PLANTS
IIJaskaIIDistrictofCoIurnIIHawiiIIPuertoRioDII\rinIslands
FIG.4MapshowingcurrentUnitedStatesdistributionofUtriculariainflata.
CourtesyoftheUSDA.
FIG.5MapshowingknownoccurrencesofUtriculariainflatainthestateof
Washington.CourtesyofKathyHamel,WashingtonStateDepartmentof
Ecology.
8
Theplant’shistoryofmvasivenessisequallyasdifficulttonaildownasit’soriginal
distribution.AtthistimeexpertsseemunsureiftheplantisnativetoNewYorkor
whetheritmayhavebeenintroducedasearlyasthemid-nineteenthcentury,oras
lateasthe1990’s.ItsresemblancetootherUtriculariaspeciesagainmaypresenta
confusingfactorindeterminingitsactualnativeandinvadedhabitats.Utricidaria
radiataissometimestreatedasUtriculariainjiatavar.radiataaddingevenfurther
confusion.Anotherpossiblecaseofpurposefulintroduction,theMissouriBotanical
gardenDatabaseshowsthataspecimenofUinflatawascollectedon12/12/1999in
Sucumbios,EcuadorbutIwasunabletoconfirmthatfinding.’ 8
InvasionProcess:
InfestationappearstobeinitsearlystagesinWashingtonState.Thefirstplants
collectedinWashingtonStatewereinHorseshoeLakeinKitsapCountyin1980.
Althoughthosespecimensweresteriletheydiddisplaythewinter-coiledbudsused
forreproduction.SpecimenshavenowbeenfoundinCowlitz,Kitsap,Mason,Pierce
andThurstonCounties,includingboththePugetSoundandDeschutesdrainages
(FIG5).
Informationonitsintroductionislimited.Jeniferparsons,sponsorofUinflataon
WashingtonStatesnoxiousweedmonitorlistandanaquaticbotanistwiththe
WashingtonStateDepartmentofEcology,notedthattheinfestationcouldnothave
happenedmuchearlierthan1980asAdolphCeskawasextensivelystudying
UtriculariainBritishColumbiaandthePacificNorthwestinthe1970’s.Eventually,
Ceska’sresearchculminatedinthepublicationofakeytotheUtriculariaspeciesof
thePNWthatdidnotincludeUinftata.Severalsources,includingtheWashington
StateDepartmentofEcology,theWesternAquaticPlantManagementSocietyand
InternationalCarnivorousPlantSocietysuggestthatacarnivorousplantenthusiast
mayhaveintroducedtheplanttoWashingtonState.Itcouldalsohavebeen
introducedaseitheranaquariumplantorwatergardenplant.InWashingtonithas
beenfoundinsmallisolatedpondsthatareunlikelytohaveseenmuch,ifany,boat
trafficandsoitismorelikelythattheplantsarenowbeingspreadviawaterfowl.
18InternetPublication/OnlineDatabase;MissouriBotanicalGarden
BPersonalcorrespondence
9
MitchellpostulatesthatNewYork’s,SprucePondlocationisequallyasunlikelya
destinationforboaters(1994)andinthatcasewaterfowlisalsothelikeliestculprit.
GiventhattheplanthasnotbeendiscoveredinanylocationsbetweenTexasand
Washingtonthisdoestendtoindicatethattheinitialintroductionwasmorelikely
causedbyhumansthanwaterfowl.
Potentialecologicaland/oreconomicimpacts:
TheimpactofUinflatacanbeextensive.It’sabilitytoformdensecover,utilize
bothdissolvednutrientsandliveprey,andit’stoleranceforawiderangeof
temperaturesandwaterchemistrymakesiteasyforthisinvasivespeciestoout
competenativeplants.Inaddition,ithasbeenshownthatcarnivorousplantsshow
anincreaseinreproductiveratesoverthosethatrelysolelyonphotosynthesis,
providinganotheradvantageoversomenativespecies(Mendezetal.1999).Theuse
oftubersasareproductivemethodgivestheplantanotherassetinthatitisableto
begingrowthearlierintheseason(Thiebaut2007)Fragmentationinit’saquatic
environmentisalsoanextremelyefficientmethodofdispersal.Nativefishand
aquaticinvertebratespeciescanbelostfromdie-offsduetoanoxicwaterconditions
orbythelossofthenativeaquaticmacrophytestheyuseforfoodandshelter.U.
injiataisoftencolonizedbyrotifersthatinhabittheareaaroundthebladdersusing
theflowofwaterfromthesuctionactiontograbsmallparticlesoffood 10.Recent
fieldandlaboratoryexperimentshavedeterminedthatUinflataaltersnutrient
cyclingandsedimentchemistrythroughsuppressionofnativemacrophytes.An
exampleistherecentlydiscoveredsuppressionofEricaulonaquaticuminsome
freshwaterlakesintheAdirondacks,aregionrecentlyinvadedbyKinflata(Urbanet
al.2006).NativeE.aquaticumreleasesoxygenintolakesediments,lowerspH,
reducesdissolvedorganiccarbonandammoniaconcentrationsviaanextensiveroot
system.Inherlaboratoryexperiments,Urban(2006)showedthatthepresenceofU
injiatareducedthebiomassofnativeE.aquaticumandconsequentlyit’sabilityto
reducepH,dissolvedsolutesandredoxpotential.E.Aquaticum,likeothercommon
isoetidsisalight-lovingmacrophyteandthepresenceofthickmatsofU.inflata
wouldtendtoreducephotosynthesisandsurvivabilitythroughexcessiveshading.
(Urbanetal.2006).Fieldexperimentsmirroredthisresult(urbanetal.2006).
10InternetPublication/OnlineDocument;BotanicalSocietyofAmerica
10
ExperimentshavealsoshownevidenceofleaflengtheninginE.aquaticuminthe
presenceofUinflatabutthiswasapparentlynotsufficienttoovercometheeffectsof
shading.InsomeinvadedAdirondacklakes,nativemacrophytespecieshavebeen
reducedbyasmuchasathird,from18to12.Inaddition,another9specieswere
significantlyreduced(urbanetal.2006).
Inadditiontoitsecologicalimpacts,Uinflatacanalsohavesignificanteconomic
impacts.Floatingmatsofvegetationalsointerferewithhumanactivity.Lower
waterqualityanddensematsofvegetationcanleadtosafetyconcernsforswimmers
andrecreationalboaters.Fishingmaybeaffectedbyexcessvegetationandpotential
lossofgamefish.Propertyvaluescanbesignificantlyaffectedwhenwaterquality
andaestheticscomeintoplay.Waterintakesandirrigationpumpscanbecome
cloggedorlakeoutletscanbecomecloggedleadingtothepotentialforlocal
flooding’ 3.Asstatedearlierinthereport,residentsofLimerickLake,Washington
afreadypaysignificantamountsinordertotryandcontrolthepopulationintheir
lake.
ManagementStrategiesandControlMethods:
Somecontrol/managementeffortshaveincludedhiringschoolkidstorakeand
pulleachplantfromthewaterA.Thistreatmentcanhaveadverseeffectshowever,as
Uinflataiscapableofreproducingviafragmentation,andmanualharvestingcan
leadtodispersedfragmentsthatdevelopintonewplants.Herbicideshavebeen
showntobeeffectiveandin1996,sonartreatment(fluridone)wastriedinLake
LimerickinMasonCounty,WA.InitiallyusedforthecontrolofBrazilianelodeaA,
itappearedtosuccessfullycontroltheUinflatapopulationforapproximately2years
buttherehavebeenobjectionstothattreatment.Fluridoneisaslow-actingsystemic
herbicidethatrequiresa7—12weektreatmentwithconstantlevelsofherbicide
beingmaintained.AccordingtotheWashingtonToxicsCoalition,fluridoneisnon-
selective,broad-spectrumherbicideandkillsnativeplantsaswellasthetargeted
invasivebydisruptingcarotenoidsynthesis’ 2.Ithasbeenshownthatgrasscarpwill
feedonSwollenBladderwortalthoughitdidnotshowanypreferenceforthis
13InternetPublication/OnlineDocument;WashingtonStateaquaticNuisanceSpecies
ManagementPlanA
PersonalCorrespondence
11
macrophyteinSilverLake,CowlitzCountyandexpertshaveadvisedthatthegrass
carpdoesnotpreferfloatingplants’ 2.Anothercontrolmethodsuggestedby
Massachusettsstateauthoritieshasbeentheuseofbenthicbarriers,butthesecan
proveproblematicbylimitinglightandupwardgrowthofnativebenthic
macrophytesandmayhavenegativeeffectsonotherbenthicorganisms.Theyalso
requirenearconstantmaintenancetoretaintheirusefulness.Accordingtothe
Massachusettswebsitethereisnoknownbiologicalcontrolforthisspecies.
Conclusion:
Uinflataisillegaltobuy,sell,ortransportinthestateofWashington 6anditison
thestate’snoxiousweedmonitorlist.Giventhisplantsabilitytoadaptandutilize
resourcesthatnativeplantscannotaccess,thismaybeinsufficienttostopitseventual
spread.MitchellnotedthatwhenUinflatawasdiscoveredinSprucePondinNew
York(1994),itwasalreadywell-establishedandcoveredperhaps10acres.He
believesitmayhavegoneundetectedforalongperiodbecausetheplantsremained
vegetativeandonlyfloweredundercertainclimaticconditionsatthatlatitude.This
raisestheconcernthatgiventhedifficultyindistinguishingitfromothernative
bladderwortswhennotinflower,itmayinfact,alreadyhavespreadfurtherthanis
readilyapparent.InresearchingonlineforthisreportIwasabletolocateUtricularia
inflataforsaleontheInternet. 8AccordingtoWSDA’sWetlandandAquaticWAC
16-752-505,
“Itisprohibitedtotransport,buy,sell,offerforsale,ortodistributeplantsorplantpartsoftheseregulatedplants,intoorwithinthestateofWashington.Itisfurtherprohibitedtointentionallytransplantwildplantsand/orplantpartsofthesespecieswithinthestateofWashington.”
It’savailabilityonlineservestoillustratetheeasewithwhichlocallawsand
regulationscanbebypassed.KathyHamelwiththeWashingtonStateDepartmentof
Ecologystatesthatuntilafewyearsagotherewasnobodycollectingaquaticplant
informationfromstatewaters.A
ShealsoconfirmedthattheONLYgroupthathas
12InternetPublication/OnlineDocument;JohnD.MadsenPhD;aquatics.org
6InternetPublication/OnlineDocument;WashingtonStateDepartmentofAgriculture
8InternetPublication/OnlineDocument;www.bestcarnivorousplants.com
APersonalcorrespondence
12
attemptedtoactivelyeradicatetheplantfromanyareainWashingtonStatearethe
residentsofLimerickLake.
Giventheplantspotentialimpactsthisseemsagraveoversight.
Inafinalactofirony,althoughSwollenBladderwortisconsideredinvasivein
WashingtonState,ithasbeendeclaredendangeredinatleast3otherareas,
Maryland(whereitislistedasanSiendangeredspeciesbytheMaryland
DepartmentofNaturalResources)”,MichiganandNewYork.(USDAwebsite).
ThisisdoublyironicasUtriculariainflataisnotnativetoMichigan.Themostlikely
explanationforthisisthesometimescontinueslistingofUtriculariaradiataasa
subspeciesofUinflata.Clearly,informationonUinflatacanbefragmentaryand
contradictory
‘InternetPublication/OnlineDocument;MarylandDepartmentofNaturalResources
13
I-.-r.
•1p__,.—,_—.-h
•p1S.
•.
FIG.6SwollenBladderwort,Utricidariainflata.
CurrentlyitislistedasbothinvasiveANDendangeredinNewYork. 7Theofficial
websitefortheUSDA’sNationalAgricultureLibrary,asitethatlistslegaldelinitions
ofinvasivespecies,GuidanceWhitepapers,concepts,terms,andcontexts,doesnot
currentlyhavealistingforUtriculariainflataasaninvasiveplant’ 6
Currentresearchandmanagementefforts,andexpertcontactinformationinPNW
Withtheexceptionoflistingthespeciesonthestate’snoxiousweedmonitorlist
anditsindusionbytheWashingtonStateDepartmentofAgricultureonthe
prohibitedplantlist,therearenocurrentmanagementeffortsinplace.U.injiatawas
foundtobepresentinawetlandadjacenttoSilverlakein2005andsoitisbelieved
thatoncetheintroducedgrasscarpdieofftheplantwilllikelyreturntothatlake.
TheredoesnotappeartobeaplantocontinuestockinggrassCarpinSilverLake.I
havebeenunabletodetermineiferadicationeffortsarestillongoingatLimerick
Lakebutitseemslikelyasitisaneffortspearheadedbylocalresidentsratherthan
anystateorlocalgoverningbody.ThelocalexpertsIcontactedwerenotawareof
anyfurthereffortsatsuppressionoreradicationanywhereinthestate.
ForfurtherinformationregardingUinflataortoreportapossiblesighting,youmay
contact:
KathyHamel,WashingtonStateDepartmentofEcology;
or
JeniferParsons,WashingtonStateDepartmentofEcology;
LiteratureCited:
‘
InternetPublication/OnlineDocument;www.gardenguides.com‘6lnternetPublication/OnlineDocument;USDANationalAgriculturalLibrary
14
AdamecL(2006)RespirationandPhotosynthesisofBladdersandLeavesofAquaticUtriculariaSpecies.PlantBiology8(6):765-769
Ceska,A.andM.A.M.Bell.1973.Utricularia(Lentibulariaceae)inthePacificNorthwest.Madrono22:74-84.
DiteD,NavratilovaJ,HajekM,ValachovicMandPukajovaD(2006)HabitatvariabilityanddassificationofUtriculariacommunities:ComparisonofpeatdepressionsinSlovakiaandtheTrebonbasin.Preslia78:331-343
FarooqMandSiddiquiSA(1966)AnatomyoffloatsofUtriculariainflexaforskvarinflexataylor.BulletinoftheTorreyBotanicalClub93:301-&
MendezMandKarissonPS(1999)Costsandbenefitsofcarnivoryinplants:insightsfromthephotosyntheticperformanceoffourcarnivorousplantsinasubarcticenvironment.Oikos86:105-112
MitchellRS,MaenzagmelchTEandBarbourJG(1994)Utricularia-inflatawait(lentibulariaceae),NewtoNew-York-State.BulletinoftheTorreyBotanicalQub121:295-297
ReinertGWandGodfreyRK(1962)ReappraisalofUtriculariainflataandU.radiata(lentibulariaceae).AmericanJournalofBotany49:213-&
ThiebautG(2007)Invasionsuccessofnon-indigenousaquaticandsemi-aquaticplantsintheirnativeandintroducedranges.AcomparisonbetweentheirinvasivenessinNorthAmericaandinFrance.BiologicalInvasions9:1-12
UrbanRA,TitusJEandZhuWX(2006)Aninvasivemacrophytealterssedimentchemistryduetosuppressionofanativeisoetid.Oecologia148:455-463
Otherkeysourcesofinfonnation:
A.KathyHamel;WashingtonStateDepartmentofEcology,emailcorrespondencewithauthor,November29,2007.
B.JeniferParsons,AquaticBotanist,WashingtonStateDepartmentofEcology,emailcorrespondencewithauthor,November29&30,2007.
1.http://www.wapms.org/plants/bladderwort.htnil
2.http://www.ecv.wa.gov/programs/WQ/plants/weeds/bladder.html
3.http://plants.usda.gov/java/proffle?svmbol=UTIN
4.http://nas.er.usgs.gov/taxgroup/ylants/default.asp
15
5.http://www.mass.gov/dcr/waterSupplv/lakeyond/faaslieet/Swollen%2OBladderwort.pdf
6.http://www.nwcb.wa.gov/documents/weed%2Olists/Prohibited%2OPIant%20Brochure%202006.pdf
7.http://www.gardenguides.com/ylants/ylant.asp?svmboFUTST2#details
8,http://www.bestcarnivorousplants.com/aldrovanda/aldrovandaforsale.htm
9.http://www.watoxics.org/issues/pesticides-in-lakes/aquatics-problems
1O.http://www.botanv.org/CarnivorousPlants/Utiicularia.php
11.http://dnrweb.dur.state.md.us/download/rteplants.pdf
12.http://www.aquaiics.org/pubs/madsen2.htni
13.http://wdfw.wa.gov/fish/ans/ansplan.pdf
14.http:1/www.ecv.wa.gov/progams/wg/plants/plantid2/descriptions/utrinf.html
15.http://www.aquariumarticles.com/read/?art2331&tUtricularia+inflata+Walt.%2C+swoflen+bladderwpzt
16.http://www.invasivespeciesinfo.gov/aquatics/main.shtml
17.http://dnrweb.dnr.state.md.us/download/rteplants.pdf
18.http://www.discoverllfe.org/mp/201?idM002685472
16
