A quick reference guide to Invasive Plant Species€¦ · purple. Black-spot fungus on leaves is...

A quick reference guide to

Invasive Plant Species

Acknowledgements

Technical input provided by:

• TheOntarioInvasivePlantCouncil• RoyalBotanicalGardens

Photosandillustrationsprovidedby:

• CreditValleyConservation• TheNatureConservancy-US• RoyalBotanicalGardens• TorontoandRegionConservation• OntarioFederationofAnglersandHunters

Text compiled and written by:

• CreditValleyConservation

Graphicdesignandproductionprovidedby:

• TorontoandRegionConservation

Coverphoto:garlicmustard(Alliaria petiolata)

Manitoba mapleAcer negundo

Norway mapleAcer platanoides

European or black alderAlnus glutinosa

European spindletree & winged euonymusEuonymus europaeus and E. alatus

non-native bush honeysucklesLonicera spp.

common & glossy buckthornRhamnus cathartica & R. frangula

dog-strangling vineCynanchum rossicum & C. nigrum

garlic mustardAlliaria petiolata

giant hogweedHeracleum mantegazzianum

Himalayan balsamImpatiens glandulifera

Japanese knotweedPolygonum cuspidatum

reed or giant manna grassGlyceria maxima

common reedPhragmites australis

goutweedAegopodium podagraria

English ivyHedera helix

periwinkleVinca minor

IntroductionSouthern Ontario’s native plants existed here for thousands of years prior to European settlement. This diverse group of plants evolved together with indigenous wildlife, adapting to local climate and soil conditions to create stable natural communities we call ecosystems.

By contrast, invasive plants come from outside this geographic area. When they are introduced, there is potential for them to establish themselves and disrupt established ecosystems forcing out native plants. Fewer native plants results in decreased biodiversity. This can mean less food and shelter for wildlife dependent on native plants. This results in a ripple effect that threatens whole ecosystems and has economic and social implications as well.

What makes a plant invasive?Not all introduced plants are invasive. Some, like the common dandelion, may be a nuisance, but do not pose a significant threat to native plants and their ecosystems. Others, including many common garden plants are benign and even beneficial. Invasive plants are a concern because they have “displacement capacity” meaning they form such dense colonies or compete so aggressively, that they force out native vegetation.

Invasive plants commonly have one or more of the following characteristics allowing them to out-compete native species:

• High annual seed production and quick establishment of dense colonies;

• Tolerance to a wide range of growing conditions;

• Ability to spread by underground roots and re-grow quickly when disturbed by pulling, cutting or fire;

• A lack of natural predators to keep their population under control in their new environment.

What can I do about invasive plants?• Learn to properly identify and manage invasive plants on your property. If you are unsure about identification, removal or control measures, contact the organizations listed below.• When selecting plants for your garden, purchase non-invasive or native plants from reputable suppliers. Native plants will provide a variety of benefits to the insects and wildlife that also depend on them. • Dispose of yard waste through your local municipality or in your backyard composter. Yard waste dumped in natural areas may contain invasive plant seeds.• Share this information with your neighbours, friends and family. The more people who know about the problem, the easier it will be to stop the introduction and spread of invasive species. • When walking or hiking in natural areas, remain on designated trails and keep pets on a leash to avoid disturbing natural vegetation or transferring invasive plants and their seeds to new areas. Always clean off your bike, hiking boots or clothes and brush your dog’s fur before leaving the natural area, to avoid accidentally spreading seeds. • Volunteers are sometimes needed to help with locating and controlling invasive species. For invasive plant management projects in your community contact the organizations listed below.

Getting Help:•Ontario Invasive Plant Council, www.ontarioinvasiveplants.ca• Stewardship Councils c/o Ontario Ministry of Natural Resources, www.mnr.gov.on.ca•Ontario Federation of Anglers and Hunters, www.ofah.org•The Invading Species Hotline, 1-800-563-7711 • Conservation Authorities, www.conservation-ontario.on.ca

Plant recognition terms

Leaf shape

Arrangement

entire toothed/serrated compoundleaf

lance shaped heart shaped tear drop shaped

opposite alternate

lobedleaf

egg shaped

Ligule- found at the inner base of the leaf, between where the leaf attaches to the main stem and the stem itself. Commonly forms a translucent membrane or a fringe of hairs.

Stem sheath- portion of leaf that wraps around and joins leaf to stem.

Lenticel- small openings in the bark of some trees that allow air exchange.

terminalbud

lateralbud

lateral budsdivergent

lateral budsappressed

Buds

Stems/Bark

Manitoba maple(Acer negundo)

Manitoba maple(Acer negundo)

compound,irregularlylobedleafcompound,irregularlylobedleaf

bark ManitobamapleseedsManitobamapleseedsbark

Manitoba maple(Acer negundo)

Plant Type: Tree.

Arrangement:Opposite.

Leaf:Compoundleaf,threetosevenleaflets,irregularlylobed.

Bark:Greyishbrownbark.Maturebarkwithnarrowfirmridges.

Seed/Flowers:Wingedseedsjoinedata<45°angle.

Buds/Stem:Eggshapedbudsarecoveredinfinewhitehairs.Youngtwigsareshinygreen-purplewithawaxywhitecoatingthatrubsoff.

Habitat:Dry,butmostlyfreshsoilsinvarioushabitats,mostofteninfloodplains.

Similar native species:Ashspecies(Fraxinus spp.) havecompoundleaveswithnolobes;terminalbuds are pointed. Elderberry (Sambucus spp.)aremulti-stemmedshrubswithclustersofberry-likefruit.

Norway maple(Acer platanoides)

Norway maple(Acer platanoides)

mature barkmature bark NorwaymapleseedsNorwaymapleseeds

whitesap-foundinleafstemwhitesap-foundinleafstem

Norway maple(Acer platanoides)

Plant type: Tree.

Arrangement:Opposite.

Leaf:Fivelobed(widerthanlong)leaf,darkgreentopurple.Black-spotfungusonleavesiscommon.White,milkysapfoundinleafstem.

Bark:Finelyridgeddarkbark.

Seed/Flowers:Wingedseed;typicalofmaples.Joinedata180ºangle.

Buds/Stem:Terminalbudisplumpandblunttippedstembudsareround,softandreddishbrown.Twigsareshinyreddishbrown.

Habitat:Drytomoistsoilsinforestandsuccessionalareas,oftenusedasurbanstreettree.

Similar native species:Sugarmaple(Acer saccharum)leavesarefivelobedandlongerthanwide.Budsonsugarmaplearesharppointed,notbluntandseedsforma“U”shape.Clearsapisfoundinleafstem.Norwaymaplebarkcanbemistakenforwhiteashwhennotinleaf.However,thebarkisconsiderablydarkerthanwhiteash.

European or black alder(Alnus glutinosa)

European or black alder(Alnus glutinosa)

leavesleaves

longstalked‘fruit’(non-native)longstalked‘fruit’(non-native)barkshowing‘lenticels’barkshowing‘lenticels’

European or black alder(Alnus glutinosa)

Plant type:Shrub/smalltree.

Arrangement:Alternate.

Leaf:Oblongshapedleafwithblunttip.

Bark:Grayishdarkbrownwithobvious,silverlenticels.

Seed/Flowers:Pine-coneshapedfruitonEuropeanalderislarge(about2cm),andonalongstalk(>1cm).

Buds/Stem:Budsare‘lightbulb’shaped.

Habitat:Moistandwetsoilsinandaroundwetlandsandwaterways.

Similar native species:Speckledalder(Alnus incana ssp. rugosa)leavesarewedgeshapedandcometoapoint.Seedconeisshortstalked(stemsare≤.5cm).Thespeckledalderisamulti-stemmedtallshrub,whileEuropeanaldergrowsmorelikeatreefromasinglestem.

winged euonymus(E. alatus)

winged euonymus(E. alatus)

runningstrawberryandEuropeanspindletreerunningstrawberryandEuropeanspindletree

two-partedseedofwinged euonymus

two-partedseedofwinged euonymus

four-partedseedofnativeburningbushandEuropeanspindletree

four-partedseedofnativeburningbushandEuropeanspindletree

Plant type:Shrub/smalltree.

Arrangement:Bothspeciesareoppositeintheir arrangement.

Leaf:Bothspecieshaveafinelytoothed,tearshapedleafthatiswidestatthemiddle.

Bark:Youngbarksmoothandgreen(E.europaeus)withprominentraisedridgesonE.alatusstems.Roughtextureandpeelingbarkwhenmature.

Seed/Flowers:Europeanspindletreehasafour-partedfruitwithyellowishflowersinsmallclusters.Wingedeuonymushasatwopartedfruit,withyellow/greenflowers.

Buds/Stem:Europeanspindletreestemsaregreenandsmooth,wingedeuonymushasprominentwingedstems.

Habitat:Drytofreshsoilsinsuccessionalareasandforests.

Similar native species:Nativestrawberrybush(E. obovatus)isagroundhuggingvine;leafwideratthetipnotthemiddle.Nativeburningbush(E. Autopurpurea) ismostoftenmistakenforEuropeanspindletree.Ithasafour-partedseed,butdifferswithdarkpurpleflowersinlargeclustersinthespring.

European spindletree & winged euonymus(Euonymus europaeus & E. alatus)

non-native bush honeysuckles(Lonicera spp.)

non-native bush honeysuckles(Lonicera spp.)

flowerflowerbarkbark

fruitfruit

non-native bush honeysuckles(Lonicera spp.)

Plant type:Shrubcanbe1.5mto4mtall.

Arrangement:Opposite.

Leaf:Allspecieshaveleaveswithsmoothmargins.Leafcanbehairyorsmooth.

Bark:Generallypapery.

Seed/Flowers:Showyflowers(variouscolours:white,pink,yellow,orange);fruittypicallytwobrightredberriesfusedtogether.

Buds/Stem:Brittlestems.Growthformtendstobemessyandtangled.Olderstemsarehollow.

Habitat:Various:drytofreshsoilsinforestandsuccessionalareas.

Similar native species:Bush(Diervilla lonicera)is<1minheight,fly(L. canadensis)is<1.5minheight,Glaucous(L. dioica) and hairy (L. hirsuta)honeysucklearebothvines.Olderstemsaresolid.Difficulttoidentifythesespecies.Consultanexpertifuncertain.

berriesberries

common & glossy buckthorn(Rhamnus cathartica & R. frangula)

common & glossy buckthorn(Rhamnus cathartica & R. frangula)

lenticelslenticels

common & glossy buckthorn(Rhamnus cathartica & R. frangula)

Plant type:Shrub/smalltree.

Arrangement:Commonbuckthornaresub-opposite(almostopposite).Glossybuckthornarealternate.

Leaf:Thecommonbuckthornleafiseggshaped,edgeoftheleafis“pebbled”(smallroundedteeth).Veinsconvergingtowardleaftop.Theglossybuckthornleafismoreslender(teardropshaped)andsmoothmargined.

Bark:Smooth,youngbarkwithprominentraisedpatchesorlenticels;roughtextureandpeelingbarkwhenmature.

Seed/Flowers:Flowersaregreen-yellowish,smallandinconspicuous.Greenberriesbecomingpurplish/blackinlatesummer,berry>1cmindiameter.

Buds/Stem:Commonbuckthornhasthorn-liketiponmanytwigs.Glossybuckthornbudshavenobudscalesandlackthornytipstotwigs.

Habitat: Various-forest,thickets,meadows,drytomoistsoils.

Similar native species:Nativedogwoods,whichlackthethorny“tip”.Nativedogwoodsaretrulyoppositeinarrangementoftwigs;onlyalternateleaved(pagoda)dogwoodhasalternatebranching.

dog-strangling vine(Cynanchum rossicum & C. nigrum)

dog-strangling vine(Cynanchum rossicum & C. nigrum)

C. rossicumflowersC. rossicumflowers

seedpodsseedpods

dog-strangling vine(Cynanchum rossicum & C. nigrum)

Plant type:Herb,twiningvine.

Arrangement:Opposite.

Leaf:Lanceshaped,smoothmargin(edge).

Bark:n/a.

Seed/Flowers:Beanshapedseedpodwithseedsattachedtodowny‘umbrellas’.Flowers-pink(C. rossicum) or purple (C. nigrum)withfivepetals.

Buds/Stem:n/a.

Habitat:Drytomoistsoils;moredominantinmeadowsandwoodlandedges.

Similar native species:Swampmilkweed(Asclepias incarnata),isanuprightplant,typicallyfoundinwetlandhabitats.

garlic mustard(Alliaria petiolata)

garlic mustard(Alliaria petiolata)

young/firstyeargrowthyoung/firstyeargrowth secondyeargrowth&flowerssecondyeargrowth&flowers

garlic mustard(Alliaria petiolata)

Plant type:Herb.

Arrangement:Alternate.

Leaf:Sawtoothlikeedge,elongatedheartshapewithprominentveins.Garlic/onionsmellwhencrushed.Young(firstyear)leavesarekidneyshaped.

Bark:n/a.

Seed/Flowers:Clusterofsmallwhiteflowerswithfourpetals.Smallblack<1mmroundedseedfoundinelongated‘tube-like’seedpods(similartoabeanpod).

Buds/Stem:n/a.

Habitat:Various–drytomoistsoils,inallhabitattypes,lessofteninmeadows.

Similar native species:n/a.

flowerandleavesflowerandleaves

giant hogweed(Heracleum mantegazzianum)giant hogweed

(Heracleum mantegazzianum)

stemwithpurplespotsstemwithpurplespots youngstemyoungstem

giant hogweed(Heracleum mantegazzianum)

Plant type:Herb.Matureplantscanbeover3mtall.

Arrangement:Alternate.

Leaf:Lobedleaf1-2mwide,lobessharp-pointed.

Bark:n/a.

Seed/Flowers:Small,whiteflowersinalargeumbrella-shapedcluster,.75mwide.

Buds/Stem:Hairystemwithpurplespots.

Habitat:Freshtowetsoilsinforests,swamps,meadows,marshes.

Similar native species:Cowparsnip(Heracleum maximum)–hassmallerflowers,nopurplespotsonstems.Angelica(Angelica atropurpurea)hasarounded-toppedflowerclusterandleavesdividedintomanyleafletsandthestemishairless.

Donottouchthisplantbecauseitispoisonous.Ifyoudo,washyourskinimmediatelyincoolsoapywateranddonotexposetheareatosunlight.

Himalayan balsam(Impatiens glandulifera)

Himalayan balsam(Impatiens glandulifera)

flowerflower

HimalayanbalsamflowerandstemHimalayanbalsamflowerandstemnativejewelweedflowerandstemnativejewelweedflowerandstem

Himalayan balsam(Impatiens glandulifera)

Plant Type:Herb,1-3minheight.

Arrangement:Alternate.

Leaf:Lanceshapedleafwithsharplytoothededges.

Bark:n/a.

Seed/Flowers:Flowers-pink,largeandshowy.

Buds/Stem:Fleshyreddishstem.

Habitat:Wetandmoistsoilsinwetlandsandfloodplains.

Similar native species:Touch-me-notsorjewelweeds(Impatiens capensis)-haveorangeoryellowflowers.Leafmoreoblongshapedandcoarselytoothed.

Japanese knotweed(Polygonum cuspidatum)

Japanese knotweed(Polygonum cuspidatum)

typicalgrowthformtypicalgrowthform

stemstem flowerflower

Japanese knotweed(Polygonum cuspidatum)

Plant Type:Herb,2-4minheight.

Arrangement:Alternate.

Leaf:Teardropshaped,sharppointed,darkgreen,flattenedatbase.

Bark:n/a.

Seed/Flowers:Floweringstalkofmanysmallgreenish-whiteflowers.

Buds/Stem:Largeplantwitha‘bamboo-like’stem.Stemlightgreenmaturingtotancolour.

Habitat:Moisttowetsoilsfoundinwetlands,water-coursesandroadsideditches.

Similar native species: none.

reed or giant manna grass(Glyceria maxima)

reed or giant manna grass(Glyceria maxima)

entire plantentire plant

tube-likeinfoldtube-likeinfoldflowerclusterflowercluster

reed or giant manna grass(Glyceria maxima)

Plant type:Grass.Matureplantsgrowover1.5m.

Arrangement:Alternate.

Leaf:Stemsheathsnearthebaseareslightlyrough.Ligulewhenpulledfromstemisinfolded(tube-like).Basereddishinspring,butfadingasseasonprogresses.Red/purpletingeoftenstilldetectableonoutersheathatbaseofsteminlateseason.Stemsarerobust;fleshyandthick.Incrosssectiontheyaresomewhatflattenedorovalinshape.

Bark:n/a.

Seed/Flowers:Uprightwithacascadingbroomlike‘flower’head.

Buds/Stem:n/a.

Habitat:Moisttofreshsoilsinopenwetlandsandedgesofriverbank.

Similar native species:Thenativespeciesofmannagrass(Glyceria sp.), includingtallnorthern,easternandrattlesnakegrass,havesmoothstemsheathsandfloweringheadstendtobendoverandnotstandupright.Rarelydothesenativespeciesexceed1.5minheight.

“flower”head“flower”head ligule

close-upofflower

common reed(Phragmites australis)

common reed

common reed(Phragmites australis)

Plant type:Grass.

Arrangement:Alternate.

Leaf:Broadleaf>1cmwide.

Bark:n/a.

Seed/Flowers:Densecascading‘broom-like’flowerhead.‘Cottony’inappearancewhenmature.

Buds/Stem:Stemsroughandridged,liguleadenselyhairyband.Hairybandlessconspicuouslaterinseason.Matureplants>3mtall.

Habitat:Moisttowetsoils.Foundinwetlands,water-coursesandroadsideditches.

Similar native species:Speciesofmannagrass(Glyceria sp.)includingtallnorthern,easternandrattlesnakegrass. Anativecommonreedexistsbuthasasmoothstemandtheliguleisnothairy.Itisalsoquiterare.

non-variegatedformnon-variegatedform

“umbrella-like”flower;variegatedform“umbrella-like”flower;variegatedform

goutweed(Aegopodium podagraria)

goutweed

goutweed(Aegopodium podagraria)

Plant type:Herb.

Arrangement:Alternate.

Leaf:Compoundleafwithserratededges,canbenon-variegatedorvariegatedgreenandwhite.

Bark:n/a.

Seed/Flowers:Flattopped‘umbrellalike’flowerheadwithmanysmallwhiteflowers.

Buds/Stem:n/a.

Habitat:Various–drytofreshsoilsinforestandsuccessionalareas.Anescapeefromresidentialgardens.

Similar native species: Water hemlock (Cicuta maculata) –foundinwetareas.Angelica(Angelica atropurpurea)hassimilarcompoundleavesbutgrowsupto2mtall.Goldenalexanders(Zizia aurea)isararenativeplantfoundinfloodplainswithsimilarbutmoreslenderleavesandyellowflowersinMaytoJune.

vine-likegrowthformvine-likegrowthform

English ivy(Hedera helix)

English ivy(Hedera helix)

English ivy(Hedera helix)

Plant Type:Herb/Vine.

Arrangement:Alternate.

Leaf: Three-lobedevergreenleafwithlightcolouredveins.

Bark:n/a.

Buds/Stem:Growsasgroundcoverandvine.

Habitat:Avarietyofsoilsfromdrytofreshinsuccessionalandforestedhabitats.Anescapeefromresidentialgardens.

Similar native species: none.

periwinkle(Vinca minor)

periwinkle(Vinca minor)

leavesleaves

flowersflowers

periwinkle(Vinca minor)

Plant type:Herb.

Arrangement:Opposite.

Leaf:Lanceshaped,shiny,evergreen.

Bark:n/a.

Seed/Flowers:Showyblue/purpleflowers.

Buds/Stem:Acreeping,trailinggroundplant.

Habitat:Drytofreshsoilsinsuccessionalareas,forestsandalongstreamsandwetlands.Typicallyassociatedwithresidentialgardens.

Similar native species:Wintergreen(Gaultheria procumbens)hassimilarleaves,buthasanobviousmintysmellwhentheleafiscrushed.Partridgeberry(Mitchella repens)isalsofoundinforests.Similarleavesbutmoreroundtoegg-shapedwithprominentpaleveins,flowersarewhitefollowedbyredberries.

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