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NorthwestMontanaAquaticSpeciesGuide

SubmergedAquaticPlants/AlgaeNorthernWatermilfoil(native)Myriophyllumsibiricum

EurasianWatermilfoil(invasive)Myriophyllumspicatum

Coontail(native)Ceratophyllumdemersum

Muskgrass/Stoneworts(native)Charaspp./Nitellaspp.

SagoPondweed(native)Stuckeniapectinate

Richardson’sPondweed(native)Potamogetonrichardsonii

White-stemmedPondweed(native)Potamogetonpraelongus

Curly-leafPondweed(invasive)Potamogetoncrispus

Non-nativeMilfoil• Square-liketips• Morethan13leafletpairs

NativeMilfoil• Moreangledtips• Fewerthan13leafletpairs

• Alternateleaves,roundedleaftips• Green/reddish-brownleaves• Toothed,wavyleafmargin

• Alternate,pointedleaves• Leavesclaspstraightstems• Smooth,wavyleafmargin

• Forkedleaves• Whorled5-12leaves

• Whorledleaf-likefilaments• Chara–pungentodor

• Thin5-30cmlongleaves• Nofloatingleavesonsurface

• Whorlsof4leaves• ≥13leafletpairsperleaf• Collapseswhenoutofwater

Macroalgae

• Alternate,pointedleaves• Zig-zaginternodesonstem• Smooth,wavyleafmargin

• Whorlsof4leaves• <13leafletpairsperleaf• Erectwhenoutofwater

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NorthwestMontanaAquaticSpeciesGuide

SubmergedAquaticPlants/AlgaeCommonElodea(native)Elodeacanadensis(Common)

WesternElodea(native)Elodeanutallii

Hydrilla(undetectedinvasive)Hydrillaverticillata

BrazilianElodea(undetectedinvasive)Elodeadensa

Watershield(native)Braseniaschreberi

FragrantWaterLily(invasive)Nymphaeaodorata

YellowFloatingHeart(undetectedinvasive)Nymphoidespeltata

• Whorlsof3-8leaves(typically5)

• Saw-toothedleafmargins• Pointedleaves5-20mmlong,<2.5mmwide

• Whorlsof3-6leaves(typically4)• Finelytoothedleafmargins• Leaves25-32mmlong,<7mmwide

• Growsupto2minlength• Whorlsof3narrowleaves• Finelyserratedleafmargins

Leaves6-15mmlong,1.5-4mmwide

• Broadlyelliptictoovalleaves,4-12cmlong,3-8cmwide

• Leaveshavelongpetiolesattachedalternatelytobranches

• Relativelysmall,purplish,manypistilledflowers

• Solitaryflowersheldjustabovethewateronlongpeduncles

• Flowerstypicallyhave3sepalsand3reddish-purplepetals(1-1.5cmlong)

• Stout,branchingstemsupto2.5mmthick

• Heart-shapedtocircularfloatingleaves,5-15cm

• Yellowflowerswithfivefringedpetals

• Leavesarisefromrhizomes,usuallyoppositeandunequal

• Largenearlyorbicularleaves,8-20cm

• Marginsaresmoothandbasesareheart-shaped

• Flowershaveatleast17whiteshowypetalsandfloatwithlongpeduncles

• Rhizomescantoleratesomedesiccation

Leaves6-13mmlong,<1.5mmwide

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NorthwestMontanaAquaticSpeciesGuide

EmergentorSubmergentAquaticPlantsBristlySedge(native)Carexcomosa

HardstemBulrush(native)Schoenoplectusacutus

FloweringRush(invasive)Butomusumbellatus

WesternBlueIris(native)Irismissouriensis

BroadleafCattail(native)Typhalatifolia

YellowFlagIris(invasive)Irispseudacorus

• Round/taperedstems,upto2m• Leafbladesreducedtoscales• Smallclusterofspikelets

• Roundstems,upto1.5m• Triangularleavesthattwistattips• Clusterof20-50pinkflowers

• Tufted,erectstems,upto1m• Leavesupto12mmwide• 5-9noddingspikes

• Plants1-1.5mtall• Basalleavesemergeinafan-likearrangement

• Smoothedged,flattenedsword-likeleaveswithapointedtipandraisedmidrib

• Largepaletodeepyellowflowers• 2.5-10cmlongthree-angledcylindricalcapsule

• Smoothdisc-shapedbrownseeds

• Plants1-2mtall• 6-23mmwideglaucousleaves• Broad,flat,sheathing,andpalegrayish-greenleaves

• 7-15cmlongspikes

• Plants10-50cmtall• Basalleavesemergeinafan-likearrangement

• 4-6cmlongsepals,whitishwithayellowmidstripeandblueveinsandmargins

• 3-4cmlongbluepetals• 2-4cmlongellipsoidcapsule

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NorthwestMontanaAquaticSpeciesGuide

MolluscsPondsnails(native)Stagnicolaspp.

FaucetSnail(invasive)Bithyniatentaculata

NewZealandMudsnail(invasive)Potamopyrgusantipodarum

WesternPearlshell(native)Margaritiferafalcata

ZebraMussel(invasive)Dreissenapolymorpha

QuaggaMussel(invasive)Dreissenabugensis

• Upto12-15mm(0.5”)• Shellisshinypalebrown,ovalinshape,witharelativelylargeandroundedspireconsistingof5–6somewhatflattenedwhorls

• Canbeapotentialbio-foulingorganism

• Adultscanreachupto4-6mm(~0.15-0.25”)

• Upto750,000snailspersquaremeter

• Canmakeupto95%ofthemacroinvertebratepopulation

• Reproducesasexually-itonlytakesonetostartanewpopulation

• Widelydistributed,variedhabitat• Size/shapevaries,upto45mm• Tolerateanaerobicconditions• Displaysfoldedcolumella

• SpeciesofConcern(onlynativemusselfoundwestofthedivide)

• Elongate,compressed,dark,andslightlyconcaveonventraledge

• Weaklydevelopedteethandapurplenacre

• Normally50-85mm,10cmmax

• Small,triangular,stripedshell• <50mm(~2”)• Smoothshellsurfaceexceptforconcentricwrinklesandgrowthrings

• Foundindenseaggregationsattachedbybyssalthreads

• Small,triangular,withroundedcarinabetweenventralanddorsalsides

• <50mm(~2”)• Colorpatternsvarywithblack,cream,orwhitebands

• Falloverwhenplacedonitsside-willnotsitflat.Zebramusselswillstandonedge

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NorthwestMontanaAquaticSpeciesGuide

CrayfishSignalCrayfish(native)Pacifastacusleniusculus

VirileCrayfish(invasivetoWesternMT)(nativetoEasternMT)Orconectesvirilis

RustyCrayfish(invasive)Orconectesrusticus

AmphibiansWesternBorealToad(native)Anaxyrusboreas

ColumbiaSpottedFrog(native)Ranaluteiventris

N.AmericanBullfrog(invasive)Ranacatesbeiana

RockyMountainTailedFrog(native)Ascaphusmontanus

PacificTreeFrog(native)Pseudacrisregilla

Long-toedSalamander(native)Ambystomamacrodactylum

• Upto15cm(6”)inlength• Rustyspotonsidesofcarapace

• Upto11cm(4¼”)• Greentobrownskinwithreddishbrownwarts

• Horizontalpupils

• Upto15cm(6”)inlength• Orange/redclawtips

Photo credit: Jarek Tuszynski (CC BY-SA 3.0)

• Upto15cm(6”)inlength• Whitepatchnearclawhinge• Blueishtoreddishbrown

• Upto20cm(8”)• Greentobrownish-greenwithdarkspotsandbandsacrosslegs

• Creamtoyellowishunderside

• Upto10cm(4”)• Darkbrown,grayoroliveskinwithdarkspots

• Undersideoflegsarered

• Upto5cm(2”),darkYinbetweeneyes

• Green,brown,grey,reddish,orbronze

• Eyelinefromnostriltoshoulder

• Upto5cm(2”),bumpytextureonskin

• Greyorbrown• Wideoutertoeonhindfoot

• Upto8.25cm(3.25”),darkgreytoblack

• Greentoyellowstripedownthemiddleofitsback(rarelyabsent)

• Longtoeonhindfoot