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.
Scientific NameSynonymCommon NameS RankNew England RankG RankReason
Acalypha virginica Three-seeded MercuryS1S2 G5Uncommon
Acer nigrumAcer saccharum ssp. nigrum; Acer saccharum var. nigrumBlack MapleS3 G5MESA-Delisted
Achillea millefolium var. lanulosaAchillea millefolium ssp. lanulosa; Achillea lanulosaSeaside YarrowS3S4 G5T5MESA-Delisted
Agrimonia rostellata Small-beaked AgrimonySNR G5Introduced?
Amelanchier intermediaAmelanchier intermediaIntermediate Shadbush, Intermediate ServiceberrySNR GNATaxonomic Issue
Amelanchier nantucketensisAmelanchier x nantucketensisNantucket ShadbushS31G3QMESA-Delisted
Angelica lucidaCoelopleurum lucidumSeaside-angelicaS2?INDG5Uncommon
Asclepias tuberosa Orange Milk-weedS43G5?MESA-Delisted
Athyrium asplenioidesAthyrium filix-femina var. asplenioides; Athyrium asplenioidesSouthern Lady-fernS2? G5T5Uncommon
Atriplex glabriusculaAtriplex glabriuscula var. glabriusculaProstrate OracheS1S2 G4Uncommon
Betula cordifoliaBetula cordifoliaHeart-leaf Paper-birchSNR G5T5Uncommon
Betula nigra River BirchS32G5Uncommon
Bidens beckiiBidens beckiiWater MarigoldS2 G5Uncommon
Boechera strictaBoechera strictaDrummond's RockcressS2S3 G5Uncommon
Bolboschoenus fluviatilisBolboschoenus fluviatilis; Scirpus fluviatilisRiver BulrushS2 G5MESA-Delisted
Bolboschoenus novae-angliaeScirpus subterminalis var.cylindricus; Scirpus cylindricus; Bolboschoenus novae-angliae; Bolboschoenus x novae-angliae; Scirpus novae-angliaeLong-stalked BullrushS2?2G5Uncommon
Botrychium angustisegmentumBotrychium lanceolatum ssp.angustisegmentum; Botrychium angustisegmentumNarrow Triangle Grape-fernS2S3 G5T4Uncommon
Botrychium matricariifoliumBotrychium matricariaefoliumDaisy-leaf MoonwortS2? G5Uncommon
Botrychium oneidenseSceptridium oneidenseBlunt-lobed Grape-fernS1S2INDG4Uncommon
Botrychium simplex Least MoonwortS1S2 G5Uncommon
Botrychium tenebrosumBotrychium tenebrosumSwamp MoonwortS1S2 G5T4?QUncommon
Bouteloua curtipendula Side-oats Gamma grassSNR2G5Introduced?
Calamagrostis canadensis var. macouniana Macoun's ReedgrassSNR G5T5?Uncommon
Calopogon tuberosusCalopogon pulchellusGrass-pinkSNR G5Uncommon
Calystegia silvatica ssp. fraternifloraCalystegia silvatica ssp. fraterniflorusShort-stalked False BindweedS22G5T5Historic Rediscovered
Cardamine bulbosaCardamine rhomboideaSpring-CressS2S3 G5Uncommon
Cardamine maximaDentaria maximaThree-leaved ToothwortS2?IND.G5Uncommon
Carex abscondita Concealed SedgeS2? G4G5Uncommon
Carex aestivalis Summer-sedgeS2S3 G4Uncommon
Carex aquatilis var. substrictaCarex substrictaWater-sedgeSNR G5TNRUncommon
Carex bicknellii Bicknell's SedgeS1S2IND.G5Uncommon
Carex buxbaumii Buxbaum's SedgeS2? G5Uncommon
Carex cristatella Crested SedgeS2? G5Uncommon
Carex debilis var. debilisCarex debilisSouthern Stalked SedgeSNR G5T5Uncommon
Carex deflexa Mountain SedgeS1 G5Historic Rediscovered
Carex diandra Panicled SedgeS1S2 G5Uncommon
Carex emoryi Emory's SedgeS1 G5Uncommon
Carex exilis Bog SedgeS2S3 G5Uncommon
Carex garberi Elk SedgeS12(a)G5Uncommon
Carex haydenii Hayden's SedgeS1S2 G5Uncommon
Carex limosa Mud SedgeS2? G5Uncommon
Carex molesta Troublesome SedgeS1? G4Uncommon
Carex prairea Praire-sedgeS1? G5Uncommon
Carex retrorsa Hooked SedgeS2S3 G5Uncommon
Carex sparganioides Bur-sedgeS4 G5Uncommon?
Carex squarrosa Squarrose SedgeS1 G4G5Historic Rediscovered
Carex viridula ssp. viridula Little Green SedgeS1S2 G5T5Uncommon
Caulophyllum giganteumCaulophyllum thalictroides var. giganteumEarly Blue CohoshS2S3 G4G5Uncommon
Chenopodium simplexChenopodium hybridum; Chenopodiastrum simplexMaple-leaf GoosefootS3? G5Uncommon
Chenopodium standleyanum Woodland-goosefootSNRIND.G5Introduced?
Cirsium horridulum var. horridulum Yellow ThistleS2S3 G5T5Uncommon
Coeloglossum virideHabenaria viridis; Dactylorhiza viridisFrog-orchisS3 G5Uncommon
Corema conradii Broom CrowberryS3 G4MESA-Delisted
Coreopsis rosea Pink TickseedS31G3Uncommon
Crataegus keepii Keep's HawthornSNR GNRUncommon?
Crataegus stonei Stone's HawthornS14GNRHistoric Rediscovered
Crocanthemum dumosum Bushy RockroseS31S3MESA-Delisted
Cuscuta coryli Pondshore-dodderS1?2G5?Uncommon
Cuscuta polygonorum Smartweed-dodderS3S4 G5Introduced?
Cyperus odoratusTorulinium odoratumSaltmarsh FlatsedgeS1S2IND.G5MESA-Delisted
Cyperus polystachyos Texas FlatsedgeS2S3 G5Uncommon
Cyperus retrorsus Pine Barren FlatsedgeS1? G5Uncommon
Cystopteris laurentianaCystopteris fragilis var. laurentiana; Cystopteris x laurentianaLaurentian Bladder FernS2S3 G3Uncommon
Desmodium canescens Hoary Tick-trefoilS32G5Uncommon
Dichanthelium acuminatum ssp. acuminatum Auburn Panic-grassS1? G5T5Uncommon
Digitaria cognata ssp. cognataDigitaria cognata ssp. cognata; Leptoloma cognatum var. cognatum; Leptoloma cognatumFall Witch-grassSNR G5T5Introduced?
Dioscorea villosa Wild YamSNR G4G5Introduced?
Diplazium pycnocarponAthyrium pycnocarpon; Homalosorus pycnocarposGlade FernS3 G5MESA-Delisted
Dryopteris campylopteraDryopteris austriacaMountain Wood-fernS3? G5Uncommon
Dryopteris goldiana Goldie's FernS3 G4G5MESA-Delisted
Elatine triandraElatine triandra var. triandraEuropean WaterwortSNR G5Introduced?
Eleocharis engelmannii var. detonsa Englemann's Spike-rushS1S2 G4G5TNRUncommon
Eleocharis engelmannii var. engelmannii Englemann's Spike-rushS1S2 G4G5TNRUncommon
Eleocharis erythropoda Redfoot Spike-rushS3 G5MESA-Delisted
Eleocharis melanocarpa Black-fruited Spike-rushS3 G4MESA-Delisted
Eleocharis rostellata Beaked or Saltmarsh SedgeS2?IND.G5Uncommon
Elymus macgregorii Early Wild RyeS2? GNRUncommon
Elymus trachycaulus ssp. trachycaulusElymus trachycaulus ssp. teslinensis; Agropyron trachycaulum; Agropyron trachycaulum var. trachycaulum; Agropyron trachycaulum var. novae-angliaeSlender Wild RyeSNR G5T5Uncommon
Equisetum palustre Marsh HorsetailSNR G5Historic Rediscovered
Equisetum pratense Meadow-horsetailS2 G5Uncommon
Equisetum variegatum ssp. variegatumEquisetum variegatum ssp. variegatumVariegated Scouring RushS3 G5T5MESA-Delisted
Eragrostis capillaris Lace-grassS2?IND.G5Uncommon
Erechtites hieraciifolius var.megalocarpusErechtites hieraciifolius var.megalocarpusSeaside PilewortS2S3 G5T3Uncommon
Eurybia radulaAster radulaRough AsterS1S2 G5Uncommon
Fuirena pumila Annual Umbrella-sedgeS33G4MESA-Delisted
Galearis spectabilisOrchis spectabilisShowy OrchisS2S3 G5Uncommon
Gentiana linearisGentiana saponaria var. linearisNarrow-leaved GentianS2? G4G5Uncommon
Gentianella quinquefoliaGentiana quinquefoliaStiff GentianS2S32G5Uncommon
Geranium bicknellii Bicknell's Crane's BillS2S3 G5Uncommon
Geum virginianum Virginia AvensS2? G5Uncommon
Hedeoma hispidaHedeoma hispidumRough PennyroyalS1 G5Introduced?
Helenium autumnale Common SneezeweedS3? G5Uncommon
Heteranthera dubiaZosterella dubiaWater Star-grassS2S3 G5Uncommon
Hottonia inflata FeatherfoilS3 G4Uncommon
Hypopitys lanuginosa Hairy Pine-sapSNR GNRUncommon?
Iris prismatica Slender blue flagSNR G4G5Uncommon
Isotria verticillata Large Whorled PogoniaS3S4 G5MESA-Delisted
Juglans cinerea ButternutS4?IND.G4Uncommon
Juncus ambiguusJuncus bufonius var. halophilusSeaside Toad-rushS1? G5Historic Rediscovered
Juncus biflorusJuncus marginatus var. biflorusTwo-flowered RushSNR G5Taxonomic Issue
Juncus nodosus Knotted RushSNR G5Uncommon
Juncus torreyi Torrey's RushSNR2G5Introduced?
Juniperus horizontalis Prostrate JuniperSNR G5Introduced?
Lactuca hirsuta Hairy Wild LettuceS2S3 G5?Uncommon
Lathyrus palustris Vetchling, Marsh-peaSNR G5Uncommon
Lechea minor Thyme-leaf PinweedS2S3IND.G5Uncommon
Lespedeza angustifolia Narrow-leaved Bush-cloverS3? G5Uncommon
Lespedeza frutescens Violet Bush-cloverS3 G5MESA-Delisted
Lespedeza stuevei  S1IND.G4?Historic Rediscovered
Lilaeopsis chinensis LilaeopsisS2? G5Uncommon
Linum intercursum Sandplain FlaxS3 G4MESA-Delisted
Linum striatum Panicled Yellow Flax, Ridgestem Yellow FlaxS2S3 G5Uncommon
Liparis loeselii Loesel's TwaybladeSNR G5Uncommon
Lobelia kalmii Brook-lobeliaS2S3 G5Uncommon
Lonicera sempervirens Trumpet HoneysuckleSNR G5Introduced?
Lonicera villosaLonicera caerulea var. villosaMountain Fly-honeysuckleSNR G5Uncommon?
Lupinus perennis Wild LupineS3S43G5Uncommon
Luzula bulbosaLuzula multiflora var. bulbosa; Luzula campestris var. bulbosaBulbous Wood-rushS2? G5Uncommon
Luzula multiflora ssp. frigida Boreal Wood-rushSNR G5T5Uncommon
Lycopus amplectens Sessile Water-horehoundS2S3 G5Uncommon
Lythrum alatum Winged LoosestrifeS1? G5Uncommon
Maianthemum trifoliumSmilacina trifoliaThree-leaved Solomon's SealS3? G5Uncommon
Menispermum canadense MoonseedS3 G5Uncommon
Myriophyllum sibiricumMyriophyllum exalbescensNorthern Water-milfoilS1S2 G5Uncommon
Nabalus albusNabalus albusWhite LettuceSNR G5Uncommon
Orthilia secundaPyrola secunda; Orthilia secunda var. secundaOne-sided Pyrola/One-sided WintergreenSNR G5Uncommon
Parietaria pensylvanica Rock-pellitoryS2S3 G5Uncommon
Paronychia fastigiata var. fastigiata Hairy Forked ChickweedSNR G5T5Introduced?
Paspalum setaceum var. psammophilum Sand Bead-grassS2S32G5T4?Uncommon
Paspalum setaceum var. setaceum Small Fruited Bead-grass or Slender Bead-grassS3? G5T5Uncommon
Pellaea atropurpurea Purple Cliff-brakeS3 G5MESA-Delisted
Phragmites australis ssp. americanusPhragmites americanusPhragmites, North American ReedS3 G5T5Uncommon
Pinus resinosa Red PineS2S3 G5Uncommon
Piptochaetium avenaceumStipa avenaceaBlack OatgrassSNR G5Uncommon
Plantago pusilla Dwarf PlantainS1? G5Introduced?
Platanthera aquilonis North Wind Bog OrchidSNR G5Uncommon
Platanthera blephariglottisHabenaria blephariglottisWhite-fringed OrchidSNR G4G5Uncommon
Platanthera hookeriHabenaria hookeriHooker's OrchisS2? G4Uncommon
Platanthera huronensisPlatanthera huronensisNorthern Green OrchisS2? G5T5?Uncommon
Platanthera macrophyllaPlatanthera macrophylla; Habenaria macrophyllaLarge Round-leaved OrchisS2? G5T4Uncommon
Platanthera orbiculataHabenaria orbiculataRound-leaved Orchis or OrchidS1S2 G5Uncommon
Podophyllum peltatum May-appleSNR2G5Introduced?
Podostemum ceratophyllum ThreadfootS2 G5MESA-Delisted
Polygala nuttallii Nuttall's MilkwortS3 G5MESA-Delisted
Polygala verticillata Whorled MilkwortS2S3IND.G5Uncommon
Polygonum tenue Rock KnotweedS2S3 G5Uncommon
Populus balsamifera ssp. balsamiferaPopulus balsamiferaBalsam-poplarS2S3 G5T5Uncommon
Potamogeton gemmiparusPotamogeton pusillus var. gemmiparus; Potamogeton gemmiparusTiny PondweedS2?IND.G5T3Uncommon?
Potamogeton obtusifolius Blunt-leaved PondweedS1? G5Uncommon
Pseudognaphalium macouniiGnaphalium macouniiClammy EverlastingS1S2 G5Uncommon
Pteridium aquilinum ssp. pseudocaudatumPteridium aquilinum ssp. pseudocaudatumPine Barrens BrakenSNR G5T5Uncommon
Quercus stellata Post OakS3S4 G5MESA-Delisted
Ranunculus allegheniensis Allegheny ButtercupS2?2G4G5Uncommon
Ranunculus fascicularis Early ButtercupS2? G5Uncommon
Rhododendron periclymenoidesRhododendron nudiflorum var. nudiflorum; Rhododendron nudiflorumPinxter-flowerS2? G5Uncommon
Ribes americanum Wild Black CurrantS3S4 G5MESA-Delisted
Ribes rotundifolium Round-leaved GooseberryS1?IND.G5Uncommon
Ribes triste Swamp Red CurrantS3 G5MESA-Delisted
Rosa blanda Smooth RoseS2S3 G5Uncommon
Rubus cuneifolius Sand-blackberryS1S22G5Uncommon
Rumex hastatulus Dune-sorrelSNR G5Introduced?
Sagina decumbens ssp. decumbens Trailing PearlwortSNR G5T5Introduced?
Sagina nodosa ssp. nodosa Knotted PearlwortSUIND.G5T5?Introduced?
Sagittaria rigida Mud ArrowheadS2? G5Uncommon
Salix candida Hoary WillowS3 G5MESA-Delisted
Salix pedicellaris Bog WillowS2? G5Uncommon
Salix serissima Autumn WillowS3 G5MESA-Delisted
Sanicula trifoliata Trefoil SanicleS2S3 G4Uncommon
Schoenoplectus acutus var. acutusScirpus acutusHard-stemmed BulrushS2S3 G5T5Uncommon
Schoenoplectus torreyiScirpus torreyiTorrey's BulrushS2? G5?Uncommon
Scirpus pendulus Pendulous BulrushS3 G5MESA-Delisted
Scirpus polyphyllus Appalachian BulrushS2?2G5Uncommon
Scleria reticularisScleria reticularis var. reticularisPondshore Nut-sedgeS31G4MESA-Delisted
Scutellaria parvula var. missouriensisScutellaria leonardii; Scutellaria parvula var. leonardiiSmall SkullcapSNR2G4T4Introduced?
Sedum ternatum Mountain-stonecropSNR G5Introduced?
Selaginella rupestris Rock SpikemossS3S4 G5MESA-Delisted
Silene caroliniana ssp. pensylvanicaSilene caroliniana var. pensylvanicaWild PinkS2S3 G5T4T5Uncommon
Solidago hispida Hispid GoldenrodS1 G5Historic Rediscovered
Solidago speciosa var. speciosaSolidago speciosa ssp. speciosa var. speciosaShowy GoldenrodS2S3 G5T5?Uncommon
Sparganium androcladum Shining Bur-reedS3? G4G5Uncommon
Sparganium angustifoliumSparganium emersum var. multipedunculatumNarrow-leaved Bull-reedS2S3 G5Uncommon
Sparganium fluctuans Floating Bull-reedS2S3 G5Uncommon
Spiranthes lucida Shining or Wide-leaved Ladies'-tressesS2? G5Uncommon
Spiranthes tuberosa Little Ladies'-tressesS3S4 G5MESA-Delisted
Sporobolus compositus var. compositus Tall DropseedSNR G5T5Introduced?
Sporobolus cryptandrus Sand DropseedS2? G5Uncommon
Stachys hyssopifolia Hyssop Hedge-nettleS3S4 G4G5MESA-Delisted
Stellaria borealis ssp. borealisStellaria calycantha sensu lato; Stellaria borealis var. borealisNorthern StarwortS2S3 G5T5Uncommon
Streptopus amplexifolius Clasping-leaf Twisted-stalkS3? G5MESA-Delisted
Suaeda maritima ssp. richiiSuaeda richiiRich's Sea-bliteS2S3IND.G5T3MESA-Delisted
Symphyotrichum praealtumAster praealtusWillow AsterS12G5Historic Rediscovered
Utricularia minor Lesser BladderwortS2S3 G5Uncommon
Uvularia grandiflora Large-flowered BellwortS3 G5MESA-Delisted
Verbesina alternifoliaActinomeris alternifoliaWingstemSNR G5Introduced?
Veronica serpyllifolia ssp. humifusaVeronica serpyllifolia var. humifusaNorthern Thyme-leaf SpeedwellSNR G5T5?Introduced?
Viola renifolia Kidney-leaf VioletS1S2 G5Uncommon
Viola rostrata Long-spurred VioletS2S3 G5Uncommon
Viola selkirkii Great-spurred VioletS1S2 G5Uncommon
Viola subsinuata Early Blue VioletS1S2IND.G3G5Uncommon
Wolffia borealis Northern Water-mealSNR G5Uncommon
Wolffiella gladiataWolffiella floridanaSickle Water-mealSNR2G5Uncommon
Xyris montana Northern Yellow-eyed GrassS2? G5Uncommon
Xyris smallianaXyris congdoniiQuagmire Yellow-eyed grassS4 G5Uncommon?
Zizania palustris var. palustrisZizania aquatica var. angustifoliaSlender Wild RiceS1S2 G4G5T4T5Uncommon

The conservation status of a species is designated by a number (1-5) and preceded by a letter reflecting the appropriate geographic scale of the assessment.  S Rank refers to "subnational" or the local/state status, while G Rank refers to the "global" status (looking at the species as a whole). Please see Plant Conservation Status for additional information on specific rankings.