Plant Watch List

The Plant Watch List (WL) is an unofficial, non-regulatory list of plants of known or suspected conservation concern that NHESP is interested in tracking.

Species are included on the list for a number of reasons:

  1. The species is thought to be rare, declining, or vulnerable, but there is insufficient information on the condition, number and size of populations to make a determination (termed "Uncommon" in the "Reasons" for listing field)
  2. The species was removed from the official regulatory list, but the Program believes it still is in need of some conservation attention (termed "MESA-Delisted" in the "Reasons" for listing field)  
  3. The species is uncommon and there are uncertainties about the taxonomic status (termed "Taxonomic Issues" in the "Reasons" for listing field)
  4. the species is uncommon and its status as a native or an introduced species is undecided (termed "Introduced?" in the "Reasons" for listing field)
  5. The species is recently discovered or rediscovered in the Commonwealth and is placed on the Watch List to ensure it is tracked while botanists determine whether it is appropriate for proposal to the MESA List.

Plant Watch List

Scientific NameCommon NameS RankNew England RankG RankReasonSynonym
Acalypha virginicaThree-seeded MercuryS1S2 G5UncommonAcalypha virginica var. virginica
Acer nigrumBlack MapleS3 G5MESA-DelistedAcer saccharum ssp. nigrum; Acer saccharum var. nigrum
Achillea millefolium var. lanulosaSeaside YarrowS3S4 G5T5MESA-DelistedAchillea lanulosa; Achillea millefolium var. lanulosa
Aletris farinosaColic-rootS4 G5Decreasing 
Amelanchier intermediaIntermediate Shadbush, Intermediate ServiceberrySNA GNRTaxonomic IssueAmelanchier x intermedia
Amelanchier nantucketensisNantucket ShadbushS31G3QMESA-DelistedAmelanchier x nantucketensis
Angelica lucidaSeaside-angelicaS2?IND.G5UncommonCoelopleurum lucidum
Asclepias amplexicaulisClasping MilkweedSNR G5Uncommon 
Asclepias tuberosaOrange Milk-weedS43G5MESA-Delisted 
Athyrium asplenioidesSouthern Lady-fernS2? G5T5UncommonAthyrium filix-femina var. asplenioides; Athyrium asplenioides
Atriplex glabriusculaProstrate OracheS1S2 G5UncommonAtriplex glabriuscula var. glabriuscula
Bartonia paniculata ssp. paniculataTwining ScrewstemSNRIND.G5T5UncommonBartonia paniculata var. paniculata; Bartonia paniculata
Betula cordifoliaHeart-leaf Paper-birchSNR G5UncommonBetula papyrifera var. cordifolia
Betula nigraRiver BirchS32G5Uncommon 
Bidens beckiiWater MarigoldS2 G5UncommonMegalodonta beckii
Boechera strictaDrummond's RockcressS2S3 G5UncommonBoechera angustifolia
Bolboschoenus fluviatilisRiver BulrushS2 G5MESA-DelistedScirpus fluviatilis; Schoenoplectus fluviatilis
Bolboschoenus novae-angliaeNew England BulrushS1S22G3UncommonScirpus subterminalis var. cylindricus; Scirpus cylindricus; Bolboschoenus x novae-angliae; Scirpus novae-angliae; Schoenoplectus novae-angliae
Botrychium angustisegmentumNarrow Triangle Grape-fernS2S3 G5T4T5UncommonBotrychium lanceolatum ssp. angustisegmentum; Botrychium angustisegmentum
Botrychium matricariifoliumDaisy-leaf MoonwortS2? G5UncommonBotrychium matricariaefolium
Botrychium oneidenseBlunt-lobed Grape-fernS1S2IND.G4UncommonSceptridium oneidense
Botrychium simplexLeast MoonwortS1S2 G5Uncommon 
Botrychium tenebrosumSwamp MoonwortS1S2 G5T4?UncommonBotrychium tenebrosum
Bouteloua curtipendulaSide-oats Gamma grassSNA2G5Introduced? 
Calamagrostis canadensis var. macounianaMacoun's ReedgrassSNR G5T4T5Uncommon 
Calopogon tuberosusGrass-pinkSNR G5UncommonCalopogon pulchellus
Calystegia silvatica ssp. fraternifloraShort-stalked False BindweedS22G5T5Historic RediscoveredCalystegia silvatica ssp. fraterniflorus; Convolvulus fraterniflorus; Calystegia sepium var. fraterniflora
Cardamine bulbosaSpring-CressS2S3 G5UncommonCardamine rhomboidea
Cardamine maximaThree-leaved ToothwortS2?IND.G5UncommonDentaria maxima
Carex absconditaConcealed SedgeS2? G5Uncommon 
Carex aestivalisSummer-sedgeS2S3 G4Uncommon 
Carex aquatilis var. substrictaWater-sedgeSNR G5T5UncommonCarex substricta
Carex atherodesWheat SedgeS1 G5  
Carex bicknelliiBicknell's SedgeS1S2IND.G5Uncommon 
Carex buxbaumiiBuxbaum's SedgeS2S3 G5Uncommon 
Carex cristatellaCrested SedgeS2? G5Uncommon 
Carex debilis var. debilisSouthern Stalked SedgeSNR G5T5UncommonCarex debilis
Carex deflexaMountain SedgeS1 G5Historic Rediscovered 
Carex diandraPanicled SedgeS1S2 G5Uncommon 
Carex emoryiEmory's SedgeS1 G5Uncommon 
Carex garberiElk SedgeS12(a)G5Uncommon 
Carex haydeniiHayden's SedgeS1S2 G5Uncommon 
Carex limosaMud SedgeS2? G5Uncommon 
Carex molestaTroublesome SedgeS1? G5Uncommon 
Carex praireaPraire-sedgeS1? G5Uncommon 
Carex retrorsaHooked SedgeS2S3 G5Uncommon 
Carex sparganioidesBur-sedgeS4 G5Uncommon? 
Carex viridula ssp. viridulaLittle Green SedgeS1S2 G5T5UncommonCarex viridula var. viridula
Caulophyllum giganteumEarly Blue CohoshS2S3 G4G5UncommonCaulophyllum thalictroides var. giganteum
Chenopodium simplexMaple-leaf GoosefootS3? G5UncommonChenopodium hybridum; Chenopodiastrum simplex
Chenopodium standleyanumWoodland-goosefootSNRIND.G5Introduced? 
Cirsium horridulum var. horridulumYellow ThistleS2S3 G5T5Uncommon 
Corema conradiiBroom CrowberryS3 G4MESA-Delisted 
Coreopsis roseaPink TickseedS31G3Uncommon 
Crataegus biltmoreanaBiltmore HawthornSNR G5UncommonCrataegus intricata var. biltmoreana
Crataegus keepiiKeep's HawthornSNR GNRUncommon? 
Crataegus stoneiStone's HawthornS14GNRUncommon 
Crocanthemum dumosumBushy RockroseS31G3MESA-DelistedHelianthemum dumosum
Cuscuta coryliPondshore-dodderS1?2G4Uncommon 
Cuscuta polygonorumSmartweed-dodderS3S4 G4G5Introduced? 
Cyperus odoratusSaltmarsh FlatsedgeS1S2IND.GNRMESA-DelistedCyperus odoratus var. odoratus
Cyperus polystachyosTexas FlatsedgeS2S3 G5UncommonPycreus polystachyos
Cystopteris laurentianaLaurentian Bladder FernS2S3 G3UncommonCystopteris fragilis var. laurentiana; Cystopteris x laurentiana
Desmodium canescensHoary Tick-trefoilS32G5Uncommon 
Dichanthelium acuminatum ssp. acuminatumAuburn Panic-grassS1? G5T5Uncommon 
Dioscorea villosaWild YamSNR G5Introduced? 
Dryopteris campylopteraMountain Wood-fernS3? G5UncommonDryopteris austriaca
Dryopteris goldieanaGoldie's FernS3 G5MESA-DelistedDryopteris goldiana
Elatine triandraEuropean WaterwortSNR G5Introduced?Elatine triandra var. triandra
Eleocharis engelmannii var. detonsaEnglemann's Spike-rushS1S2 G5T3?Uncommon 
Eleocharis engelmannii var. engelmanniiEnglemann's Spike-rushS1S2 G5TNRUncommon 
Eleocharis erythropodaRedfoot Spike-rushS3 G5MESA-Delisted 
Eleocharis melanocarpaBlack-fruited Spike-rushS3 G4MESA-Delisted 
Eleocharis rostellataBeaked or Saltmarsh SedgeS2?IND.G5UncommonScirpus rostellatus
Elymus macgregoriiEarly Wild RyeS2? G5Uncommon 
Elymus trachycaulus ssp. trachycaulusSlender Wild RyeSNR G5T5UncommonElymus trachycaulus ssp. teslinensis; Agropyron trachycaulum; Agropyron trachycaulum var. trachycaulum; Agropyron trachycaulum var.  novae-angliae
Equisetum palustreMarsh HorsetailSNR G5Historic Rediscovered 
Equisetum pratenseMeadow-horsetailS2 G5Uncommon 
Equisetum variegatum ssp. variegatumVariegated Scouring RushS3 G5T5MESA-DelistedEquisetum variegatum ssp. variegatum
Eragrostis capillarisLace-grassS2?IND.G5Uncommon 
Erechtites hieraciifolius var. megalocarpusSeaside PilewortS2S3 G5T3UncommonErechtites hieraciifolia var. megalocarpa
Eurybia radulaRough AsterS1S2 G5UncommonAster radula
Fuirena pumilaAnnual Umbrella-sedgeS33G5MESA-Delisted 
Gentiana linearisNarrow-leaved GentianS2? G4G5UncommonGentiana saponaria var. linearis; Dasystephana linearis
Gentianella quinquefoliaStiff GentianS2S32G5UncommonGentiana quinquefolia
Geranium bicknelliiBicknell's Crane's BillS2S3 G5Uncommon 
Geum virginianumVirginia AvensS2? G5Uncommon 
Hedeoma hispidaRough PennyroyalS1 G5Introduced?Hedeoma hispidum
Helenium autumnaleCommon SneezeweedS3? G5Uncommon 
Heteranthera dubiaWater Star-grassS2S3 G5UncommonZosterella dubia
Homalosorus pycnocarposGlade FernS3 G51985: MESA-DelistedAthyrium pycnocarpon; Diplazium pycnocarpon; Asplenium pycnocarpon; Diplaziopsis pycnocarpa
Hottonia inflataFeatherfoilS3 G4Uncommon 
Hypopitys lanuginosaHairy Pine-sapSNR G5Uncommon?Monotropa lanuginosa
Iris prismaticaSlender blue flagSNR G4UncommonLimniris prismatica
Isotria verticillataLarge Whorled PogoniaS3S4 G5MESA-Delisted 
Juglans cinereaButternutS4?IND.G3Uncommon 
Juncus ambiguusSeaside Toad-rushS1? G5Historic RediscoveredJuncus bufonius var. halophilus; Juncus bufonius var. ranarius; Juncus ranarius
Juncus nodosusKnotted RushSNR G5Uncommon 
Juncus torreyiTorrey's RushSNR2G5Introduced? 
Juniperus horizontalisProstrate JuniperSNR G5Introduced? 
Lactuca hirsutaHairy Wild LettuceS2S3 G5?Uncommon 
Lathyrus palustrisVetchling, Marsh-peaSNR G5Uncommon 
Lechea minorThyme-leaf PinweedS2S3IND.G5Uncommon 
Leptoloma cognataFall Witch-grassSNR G5Introduced?Digitaria cognata ssp. cognata; Leptoloma cognatum var. cognatum; Leptoloma cognatum; Digitaria cognata; Digitaria cognata var. cognata
Lespedeza angustifoliaNarrow-leaved Bush-cloverS3? G4Uncommon 
Lespedeza frutescensViolet Bush-cloverS3 G5MESA-DelistedLespedeza violacea
Lespedeza stuevei S1IND.G4?Historic Rediscovered 
Lilaeopsis chinensisLilaeopsisS2? G5Uncommon 
Limosella australisAtlantic MudwortSNR G5UncommonLimosella aquatica var. tenuifolia
Linum intercursumSandplain FlaxS3 G4MESA-Delisted 
Linum striatumPanicled Yellow Flax, Ridgestem Yellow FlaxS2S3 G5Uncommon 
Lobelia kalmiiBrook-lobeliaS2S3 G5Uncommon 
Lonicera sempervirensTrumpet HoneysuckleSNR G5Introduced? 
Lonicera villosaMountain Fly-honeysuckleSNR G5Uncommon?Lonicera caerulea var. villosa
Luzula bulbosaBulbous Wood-rushS2? G5UncommonLuzula multiflora var. bulbosa; Luzula campestris var. bulbosa
Luzula multiflora ssp. frigidaBoreal Wood-rushSNR G5T5Uncommon 
Lycopus amplectensSessile Water-horehoundS2S3 G5Uncommon 
Maianthemum trifoliumThree-leaved Solomon's SealS3? G5UncommonSmilacina trifolia
Menispermum canadenseMoonseedS3 G5Uncommon 
Myriophyllum sibiricumNorthern Water-milfoilS1S2 G5UncommonMyriophyllum exalbescens
Nabalus albusWhite LettuceSNR G5UncommonNabalus albus
Orthilia secundaOne-sided Pyrola/One-sided WintergreenSNR G5UncommonPyrola secunda; Orthilia secunda var. secunda
Panicum tuckermaniiTuckerman's Panic-grassSNR G3G5Taxonomic questionPanicum philadelphicum var. tuckermanii
Parietaria pensylvanicaRock-pellitoryS2S3 G5Uncommon 
Paronychia fastigiata var. fastigiataHairy Forked ChickweedSNR G5T5Introduced? 
Paspalum setaceum var. psammophilumSand Bead-grassS2S32G5T4?Uncommon 
Paspalum setaceum var. setaceumSmall Fruited Bead-grass or Slender Bead-grassS3? G5T5Uncommon 
Pellaea atropurpureaPurple Cliff-brakeS3 G5MESA-Delisted 
Phragmites australis ssp. americanusPhragmites, North American ReedS3 G5T5UncommonPhragmites americanus
Pinus resinosaRed PineS2S3 G5Uncommon 
Piptochaetium avenaceumBlack OatgrassSNR G5UncommonStipa avenacea
Platanthera aquilonisNorth Wind Bog OrchidS3S4 G5UncommonLimnorchis aquilonis
Platanthera blephariglottisWhite-fringed OrchidSNR G5UncommonHabenaria blephariglottis
Platanthera grandifloraLarge Purple-fringed OrchidS4 G5DecreasingPlatanthera grandifolia; Habenaria fimbriata; Habenaria grandiflora
Platanthera huronensisNorthern Green OrchidS2? G5T5?UncommonPlatanthera huronensis; Limnorchis huronensis
Podophyllum peltatumMay-appleSNR2G5Introduced? 
Podostemum ceratophyllumThreadfootS2 G4MESA-Delisted 
Polygala nuttalliiNuttall's MilkwortS3 G4MESA-Delisted 
Polygala verticillataWhorled MilkwortS2S3IND.G5Uncommon 
Polygala verticillata var. ambiguaAlternate MilkwortSNR2G5T5?Historic RediscoveredPolygala ambigua
Polygonum tenueRock KnotweedS2S3 G5UncommonDuravia sp. 2
Populus balsamifera ssp. balsamiferaBalsam-poplarS2S3 G5T5UncommonPopulus balsamifera; Populus balsamifera var. balsamifera; Populus tacamahacca
Potamogeton gemmiparusTiny PondweedS2?IND.G5T2Uncommon?Potamogeton pusillus var. gemmiparus; Potamogeton gemmiparus; Potamogeton berchtoldii ssp. gemmiparus
Potamogeton obtusifoliusBlunt-leaved PondweedS1? G5Uncommon 
Pseudognaphalium macouniiClammy EverlastingS1S2 G5UncommonGnaphalium macounii; Gnaphalium decurrens
Pteridium aquilinum ssp. pseudocaudatumPine Barrens BrakenSNR G5T5UncommonPteridium aquilinum ssp. pseudocaudatum; Pteridium latiusculum var. pseudocaudatum; Pteridium pseudocaudatum
Quercus stellataPost OakS3S4 G5MESA-Delisted 
Ranunculus allegheniensisAllegheny ButtercupS2?2G4Uncommon 
Ranunculus fascicularisEarly ButtercupS2? G5Uncommon 
Rhododendron periclymenoidesPinxter-flowerS2? G5UncommonRhododendron nudiflorum var. nudiflorum; Rhododendron nudiflorum
Ribes americanumWild Black CurrantS3S4 G5MESA-Delisted 
Ribes rotundifoliumRound-leaved GooseberryS1?IND.G5Uncommon 
Ribes tristeSwamp Red CurrantS3 G5MESA-Delisted 
Rosa blandaSmooth RoseS2S3 G5Uncommon 
Rubus cuneifoliusSand-blackberryS1S22G5Uncommon 
Rumex hastatulusDune-sorrelSNR G5Introduced? 
Sagina decumbens ssp. decumbensTrailing PearlwortSNR G5T5Introduced? 
Sagittaria rigidaMud ArrowheadS2? G5Uncommon 
Salix candidaHoary WillowS3 G5MESA-Delisted 
Salix pedicellarisBog WillowS2? G5Uncommon 
Salix serissimaAutumn WillowS3 G5MESA-Delisted 
Sanguisorba canadensisCanada BurnetSNR G5UncommonSanguisorba canadensis ssp. canadensis
Sanicula trifoliataTrefoil SanicleS2S3 G4Uncommon 
Schoenoplectus acutus var. acutusHard-stemmed BulrushS2S3 G5T5UncommonScirpus acutus; Schoenoplectus acutus
Schoenoplectus torreyiTorrey's BulrushS2? G4UncommonScirpus torreyi
Scirpus pendulusPendulous BulrushS3 G5MESA-Delisted 
Scirpus polyphyllusAppalachian BulrushS2?2G5?Uncommon 
Scleria reticularisPondshore Nut-sedgeS31G4MESA-DelistedScleria reticularis var. reticularis
Scutellaria parvula var. missouriensisSmall SkullcapSNR2G5T5Introduced?Scutellaria leonardii; Scutellaria parvula var. leonardii
Sedum ternatumMountain-stonecropSNR G5Introduced? 
Selaginella rupestrisRock SpikemossS3S4 G5MESA-DelistedBryodesma rupestre
Sesuvium maritimumAnnual Sea-purslaneS12G5Newly Discovered 
Silene caroliniana ssp. pensylvanicaWild PinkS2S3 G5T4UncommonSilene caroliniana var. pensylvanica; Silene pensylvanica
Solidago hispidaHispid GoldenrodS1 G5Historic Rediscovered 
Solidago speciosa var. speciosaShowy GoldenrodS2S3 G5T5UncommonSolidago speciosa ssp. speciosa var. speciosa; Solidago speciosa
Sparganium androcladumShining Bur-reedS3? G4G5Uncommon 
Sparganium angustifoliumNarrow-leaved Bull-reedS2S3 G5Uncommon 
Sparganium fluctuansFloating Bur-reedS2S3 G5Uncommon 
Spiranthes lucidaShining or Wide-leaved Ladies'-tressesS2? G4Uncommon 
Spiranthes tuberosaLittle Ladies'-tressesS3S4 G5MESA-Delisted 
Sporobolus compositus var. compositusTall DropseedSNR G5T5Introduced? 
Sporobolus cryptandrusSand DropseedS2? G5Uncommon 
Stachys hyssopifoliaHyssop Hedge-nettleS3S4 G4G5MESA-Delisted 
Stellaria borealis ssp. borealisNorthern StarwortS2S3 G5T5UncommonStellaria calycantha sensu lato; Stellaria borealis var. borealis
Streptopus amplexifoliusClasping-leaf Twisted-stalkS3? G5MESA-Delisted 
Suaeda maritima ssp. richiiRich's Sea-bliteS2S3IND.G5T3MESA-DelistedSuaeda richii
Symphyotrichum praealtumWillow AsterS12G5Historic RediscoveredAster praealtus
Symphyotrichum prenanthoidesCrooked-stem AsterS22G5MESA-DelistedAster prenanthoides
Tephrosia virginianaGoat's RueSNR G5Uncommon 
Utricularia minorLesser BladderwortS2S3 G5Uncommon 
Uvularia grandifloraLarge-flowered BellwortS3 G5MESA-Delisted 
Veronica serpyllifolia ssp. humifusaNorthern Thyme-leaf SpeedwellSNR G5T5Introduced?Veronica serpyllifolia var. humifusa
Viola renifoliaKidney-leaf VioletS1S2 G5Uncommon 
Viola rostrataLong-spurred VioletS2S3 G5Uncommon 
Viola selkirkiiGreat-spurred VioletS1S2 G5Uncommon 
Viola subsinuataEarly Blue VioletS1S2IND.G4UncommonViola subsinuata var. subsinuata; Viola emarginata var. subsinuata
Wolffia borealisNorthern Water-mealSNR G5Uncommon 
Wolffiella gladiataSickle Water-mealSNR2G4G5UncommonWolffiella floridana
Xyris montanaNorthern Yellow-eyed GrassS2? G5Uncommon 
Xyris smallianaQuagmire Yellow-eyed grassS4 G4G5Uncommon?Xyris congdonii
Zizania palustris var. palustrisSlender Wild RiceS1S2 G5T4UncommonZizania aquatica var. angustifolia

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Last updated: February 10, 2025

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