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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 Name Common Name S Rank New England Rank G Rank Reason Synonym
Acalypha virginica Three-seeded Mercury S1S2   G5 Uncommon  
Acer nigrum Black Maple S3   G5 MESA-Delisted Acer saccharum ssp. nigrum; Acer saccharum var. nigrum
Achillea millefolium var. lanulosa Seaside Yarrow S3S4   G5T5 MESA-Delisted Achillea lanulosa; Achillea millefolium var. lanulosa
Aletris farinosa Colic-root S4   G5 Decreasing  
Amelanchier intermedia Intermediate Shadbush, Intermediate Serviceberry SNR   GNA Taxonomic Issue Amelanchier intermedia
Amelanchier nantucketensis Nantucket Shadbush S3 1 G3Q MESA-Delisted Amelanchier x nantucketensis
Angelica lucida Seaside-angelica S2? IND. G5 Uncommon Coelopleurum lucidum
Asclepias amplexicaulis Clasping Milkweed SNR   G5 Uncommon  
Asclepias tuberosa Orange Milk-weed S4 3 G5 MESA-Delisted  
Athyrium asplenioides Southern Lady-fern S2?   G5T5 Uncommon Athyrium filix-femina var. asplenioides; Athyrium asplenioides
Atriplex glabriuscula Prostrate Orache S1S2   G5 Uncommon Atriplex glabriuscula var. glabriuscula
Bartonia paniculata ssp. paniculata Twining Screwstem SNR IND. G5T5 Uncommon Bartonia paniculata var. paniculata; Bartonia paniculata
Betula cordifolia Heart-leaf Paper-birch SNR   G5T5 Uncommon Betula cordifolia
Betula nigra River Birch S3 2 G5 Uncommon  
Bidens beckii Water Marigold S2   G5 Uncommon Bidens beckii
Boechera stricta Drummond's Rockcress S2S3   G5 Uncommon Boechera stricta
Bolboschoenus fluviatilis River Bulrush S2   G5 MESA-Delisted Bolboschoenus fluviatilis; Scirpus fluviatilis
Bolboschoenus novae-angliae Long-stalked Bullrush S2? 2 G5 Uncommon Scirpus subterminalis var. cylindricus; Scirpus cylindricus; Bolboschoenus novae-angliae; Bolboschoenus x novae-angliae; Scirpus novae-angliae
Botrychium angustisegmentum Narrow Triangle Grape-fern S2S3   G5T4 Uncommon Botrychium lanceolatum ssp. angustisegmentum; Botrychium angustisegmentum
Botrychium matricariifolium Daisy-leaf Moonwort S2?   G5 Uncommon Botrychium matricariaefolium
Botrychium oneidense Blunt-lobed Grape-fern S1S2 IND. G4 Uncommon Sceptridium oneidense
Botrychium simplex Least Moonwort S1S2   G5 Uncommon  
Botrychium tenebrosum Swamp Moonwort S1S2   G5T4? Uncommon Botrychium tenebrosum
Bouteloua curtipendula Side-oats Gamma grass SNR 2 G5 Introduced?  
Calamagrostis canadensis var. macouniana Macoun's Reedgrass SNR   G5T5? Uncommon  
Calopogon tuberosus Grass-pink SNR   G5 Uncommon Calopogon pulchellus
Calystegia silvatica ssp. fraterniflora Short-stalked False Bindweed S2 2 G5T5 Historic Rediscovered Calystegia silvatica ssp. fraterniflorus; Convolvulus fraterniflorus
Cardamine bulbosa Spring-Cress S2S3   G5 Uncommon Cardamine rhomboidea
Cardamine maxima Three-leaved Toothwort S2? IND. G5 Uncommon Dentaria maxima
Carex abscondita Concealed Sedge S2?   G4G5 Uncommon  
Carex aestivalis Summer-sedge S2S3   G4 Uncommon  
Carex aquatilis var. substricta Water-sedge SNR   G5TNR Uncommon Carex substricta
Carex bicknellii Bicknell's Sedge S1S2 IND. G5 Uncommon  
Carex buxbaumii Buxbaum's Sedge S2?   G5 Uncommon  
Carex cristatella Crested Sedge S2?   G5 Uncommon  
Carex debilis var. debilis Southern Stalked Sedge SNR   G5T5 Uncommon Carex debilis
Carex deflexa Mountain Sedge S1   G5 Historic Rediscovered  
Carex diandra Panicled Sedge S1S2   G5 Uncommon  
Carex emoryi Emory's Sedge S1   G5 Uncommon  
Carex exilis Bog Sedge S2S3   G5 Uncommon  
Carex garberi Elk Sedge S1 2(a) G5 Uncommon  
Carex haydenii Hayden's Sedge S1S2   G5 Uncommon  
Carex limosa Mud Sedge S2?   G5 Uncommon  
Carex molesta Troublesome Sedge S1?   G4 Uncommon  
Carex prairea Praire-sedge S1?   G5 Uncommon  
Carex retrorsa Hooked Sedge S2S3   G5 Uncommon  
Carex sparganioides Bur-sedge S4   G5 Uncommon?  
Carex viridula ssp. viridula Little Green Sedge S1S2   G5T5 Uncommon  
Caulophyllum giganteum Early Blue Cohosh S2S3   G4G5 Uncommon Caulophyllum thalictroides var. giganteum
Chenopodium simplex Maple-leaf Goosefoot S3?   G5 Uncommon Chenopodium hybridum; Chenopodiastrum simplex
Chenopodium standleyanum Woodland-goosefoot SNR IND. G5 Introduced?  
Cirsium horridulum var. horridulum Yellow Thistle S2S3   G5T5 Uncommon  
Coeloglossum viride Frog-orchis S3   G5 Uncommon. Habenaria viridis; Dactylorhiza viridis
Corema conradii Broom Crowberry S3   G4 MESA-Delisted  
Coreopsis rosea Pink Tickseed S3 1 G3 Uncommon  
Crataegus biltmoreana Biltmore Hawthorn SNR   G5 Uncommon Crataegus intricata var. biltmoreana
Crataegus keepii Keep's Hawthorn SNR   GNR Uncommon?  
Crataegus stonei Stone's Hawthorn S1 4 GNR Uncommon  
Crocanthemum dumosum Bushy Rockrose S3 1 G3 MESA-Delisted Crocanthemum dumosum
Cuscuta coryli Pondshore-dodder S1? 2 G5? Uncommon  
Cuscuta polygonorum Smartweed-dodder S3S4   G5 Introduced?  
Cyperus odoratus Saltmarsh Flatsedge S1S2 IND. GNR MESA-Delisted Cyperus odoratus var. odoratus
Cyperus polystachyos Texas Flatsedge S2S3   G5 Uncommon  
Cyperus retrorsus Pine Barren Flatsedge S1?   G5 Uncommon  
Cystopteris laurentiana Laurentian Bladder Fern S2S3   G3 Uncommon Cystopteris fragilis var. laurentiana; Cystopteris x laurentiana
Desmodium canescens Hoary Tick-trefoil S3 2 G5 Uncommon  
Dichanthelium acuminatum ssp. acuminatum Auburn Panic-grass S1?   G5T5 Uncommon  
Digitaria cognata ssp. cognata Fall Witch-grass SNR   G5T5 Introduced? Digitaria cognata ssp. cognata; Leptoloma cognatum var. cognatum; Leptoloma cognatum
Dioscorea villosa Wild Yam SNR   G4G5 Introduced?  
Diplazium pycnocarpon Glade Fern S3   G5 MESA-Delisted Athyrium pycnocarpon; Homalosorus pycnocarpos
Dryopteris campyloptera Mountain Wood-fern S3?   G5 Uncommon Dryopteris austriaca
Dryopteris goldiana Goldie's Fern S3   G4G5 MESA-Delisted Dryopteris goldieana
Elatine triandra European Waterwort SNR   G5 Introduced? Elatine triandra var. triandra
Eleocharis engelmannii var. detonsa Englemann's Spike-rush S1S2   G4G5T3? Uncommon  
Eleocharis engelmannii var. engelmannii Englemann's Spike-rush S1S2   G4G5TNR Uncommon  
Eleocharis erythropoda Redfoot Spike-rush S3   G5 MESA-Delisted  
Eleocharis melanocarpa Black-fruited Spike-rush S3   G4 MESA-Delisted  
Eleocharis rostellata Beaked or Saltmarsh Sedge S2? IND. G5 Uncommon  
Elymus macgregorii Early Wild Rye S2?   G5 Uncommon  
Elymus trachycaulus ssp. trachycaulus Slender Wild Rye SNR   G5T5 Uncommon Elymus trachycaulus ssp. teslinensis; Agropyron trachycaulum; Agropyron trachycaulum var. trachycaulum; Agropyron trachycaulum var. novae-angliae
Equisetum palustre Marsh Horsetail SNR   G5 Historic Rediscovered  
Equisetum pratense Meadow-horsetail S2   G5 Uncommon  
Equisetum variegatum ssp. variegatum Variegated Scouring Rush S3   G5T5 MESA-Delisted Equisetum variegatum ssp. variegatum
Eragrostis capillaris Lace-grass S2? IND. G5 Uncommon  
Erechtites hieraciifolius var. megalocarpus Seaside Pilewort S2S3   G5T3 Uncommon Erechtites hieraciifolia var. megalocarpa
Eurybia radula Rough Aster S1S2   G5 Uncommon Aster radula
Fuirena pumila Annual Umbrella-sedge S3 3 G4 MESA-Delisted  
Galearis spectabilis Showy Orchis S2S3   G5 Uncommon Orchis spectabilis
Gentiana linearis Narrow-leaved Gentian S2?   G4G5 Uncommon Gentiana saponaria var. linearis
Gentianella quinquefolia Stiff Gentian S2S3 2 G5 Uncommon Gentiana quinquefolia
Geranium bicknellii Bicknell's Crane's Bill S2S3   G5 Uncommon  
Geum virginianum Virginia Avens S2?   G5 Uncommon  
Hedeoma hispida Rough Pennyroyal S1   G5 Introduced? Hedeoma hispidum
Helenium autumnale Common Sneezeweed S3?   G5 Uncommon  
Heteranthera dubia Water Star-grass S2S3   G5 Uncommon Zosterella dubia
Hottonia inflata Featherfoil S3   G4 Uncommon  
Hypopitys lanuginosa Hairy Pine-sap SNR   G5 Uncommon? Monotropa lanuginosa
Iris prismatica Slender blue flag SNR   G4G5 Uncommon Limniris prismatica
Isotria verticillata Large Whorled Pogonia S3S4   G5 MESA-Delisted  
Juglans cinerea Butternut S4? IND. G3 Uncommon  
Juncus ambiguus Seaside Toad-rush S1?   G5 Historic Rediscovered Juncus bufonius var. halophilus; Juncus bufonius var. ranarius; Juncus ranarius
Juncus nodosus Knotted Rush SNR   G5 Uncommon  
Juncus torreyi Torrey's Rush SNR 2 G5 Introduced?  
Juniperus horizontalis Prostrate Juniper SNR   G5 Introduced?  
Lactuca hirsuta Hairy Wild Lettuce S2S3   G5? Uncommon  
Lathyrus palustris Vetchling, Marsh-pea SNR   G5 Uncommon  
Lechea minor Thyme-leaf Pinweed S2S3 IND. G5 Uncommon  
Lespedeza angustifolia Narrow-leaved Bush-clover S3?   G5 Uncommon  
Lespedeza frutescens Violet Bush-clover S3   G5 MESA-Delisted Lespedeza violacea
Lespedeza stuevei   S1 IND. G4? Historic Rediscovered  
Lilaeopsis chinensis Lilaeopsis S2?   G5 Uncommon  
Limosella australis Atlantic Mudwort SNR   G4G5 Uncommon Limosella aquatica var. tenuifolia
Linum intercursum Sandplain Flax S3   G4 MESA-Delisted  
Linum striatum Panicled Yellow Flax, Ridgestem Yellow Flax S2S3   G5 Uncommon  
Liparis loeselii Loesel's Twayblade SNR   G5 Uncommon.  
Lobelia kalmii Brook-lobelia S2S3   G5 Uncommon  
Lonicera sempervirens Trumpet Honeysuckle SNR   G5 Introduced?  
Lonicera villosa Mountain Fly-honeysuckle SNR   G5 Uncommon? Lonicera caerulea var. villosa
Lupinus perennis Wild Lupine S3S4 3 G5 Uncommon  
Luzula bulbosa Bulbous Wood-rush S2?   G5 Uncommon Luzula multiflora var. bulbosa; Luzula campestris var. bulbosa
Luzula multiflora ssp. frigida Boreal Wood-rush SNR   G5T5 Uncommon  
Lycopus amplectens Sessile Water-horehound S2S3   G5 Uncommon  
Lythrum alatum Winged Loosestrife S1?   G5 Uncommon  
Maianthemum trifolium Three-leaved Solomon's Seal S3?   G5 Uncommon Smilacina trifolia
Menispermum canadense Moonseed S3   G5 Uncommon  
Myriophyllum sibiricum Northern Water-milfoil S1S2   G5 Uncommon Myriophyllum exalbescens
Nabalus albus White Lettuce SNR   G5 Uncommon Nabalus albus
Opuntia cespitosa Cespitose Prickly-Pear SNR   GNR Taxonomic question Opuntia caespitosa
Orthilia secunda One-sided Pyrola/One-sided Wintergreen SNR   G5 Uncommon Pyrola secunda; Orthilia secunda var. secunda
Panicum tuckermanii Tuckerman's Panic-grass SNR   G3G5 Taxonomic question Panicum philadelphicum var. tuckermanii
Parietaria pensylvanica Rock-pellitory S2S3   G5 Uncommon  
Paronychia fastigiata var. fastigiata Hairy Forked Chickweed SNR   G5T5 Introduced?  
Paspalum setaceum var. psammophilum Sand Bead-grass S2S3 2 G5T4? Uncommon  
Paspalum setaceum var. setaceum Small Fruited Bead-grass or Slender Bead-grass S3?   G5T5 Uncommon  
Pellaea atropurpurea Purple Cliff-brake S3   G5 MESA-Delisted  
Phragmites australis ssp. americanus Phragmites, North American Reed S3   G5T5 Uncommon Phragmites americanus
Pinus resinosa Red Pine S2S3   G5 Uncommon  
Piptochaetium avenaceum Black Oatgrass SNR   G5 Uncommon Stipa avenacea
Platanthera aquilonis North Wind Bog Orchid S3S4   G5 Uncommon  
Platanthera blephariglottis White-fringed Orchid SNR   G5 Uncommon Habenaria blephariglottis
Platanthera grandiflora Large Purple-fringed Orchid S4   G5 Decreasing Platanthera grandifolia; Habenaria fimbriata; Habenaria grandiflora
Platanthera hookeri Hooker's Orchid S2?   G4 Uncommon Habenaria hookeri
Platanthera huronensis Northern Green Orchid S2?   G5T5? Uncommon Platanthera huronensis
Platanthera macrophylla Large Round-leaved Orchid S2?   G5T4 Uncommon Platanthera macrophylla; Habenaria macrophylla
Platanthera orbiculata Round-leaved Orchis or Orchid S1S2   G5 Uncommon Habenaria orbiculata
Podophyllum peltatum May-apple SNR 2 G5 Introduced?  
Podostemum ceratophyllum Threadfoot S2   G5 MESA-Delisted  
Polygala nuttallii Nuttall's Milkwort S3   G5 MESA-Delisted  
Polygala verticillata Whorled Milkwort S2S3 IND. G5 Uncommon  
Polygala verticillata var. ambigua Alternate Milkwort SNR 2 G5T5? Historic Rediscovered Polygala ambigua
Polygonum tenue Rock Knotweed S2S3   G5 Uncommon  
Populus balsamifera ssp. balsamifera Balsam-poplar S2S3   G5T5 Uncommon Populus balsamifera; Populus balsamifera var. balsamifera; Populus tacamahaca
Potamogeton gemmiparus Tiny Pondweed S2? IND. G5T3 Uncommon? Potamogeton pusillus var. gemmiparus; Potamogeton gemmiparus; Potamogeton berchtoldii ssp. gemmiparus
Potamogeton obtusifolius Blunt-leaved Pondweed S1?   G5 Uncommon  
Pseudognaphalium macounii Clammy Everlasting S1S2   G5 Uncommon Gnaphalium macounii
Pteridium aquilinum ssp. pseudocaudatum Pine Barrens Braken SNR   G5T5 Uncommon Pteridium aquilinum ssp. pseudocaudatum; Pteridium latiusculum var. pseudocaudatum
Quercus stellata Post Oak S3S4   G5 MESA-Delisted  
Ranunculus allegheniensis Allegheny Buttercup S2? 2 G4G5 Uncommon  
Ranunculus fascicularis Early Buttercup S2?   G5 Uncommon  
Rhododendron periclymenoides Pinxter-flower S2?   G5 Uncommon Rhododendron nudiflorum var. nudiflorum; Rhododendron nudiflorum
Ribes americanum Wild Black Currant S3S4   G5 MESA-Delisted  
Ribes rotundifolium Round-leaved Gooseberry S1? IND. G5 Uncommon  
Ribes triste Swamp Red Currant S3   G5 MESA-Delisted  
Rosa blanda Smooth Rose S2S3   G5 Uncommon  
Rubus cuneifolius Sand-blackberry S1S2 2 G5 Uncommon  
Rumex hastatulus Dune-sorrel SNR   G5 Introduced?  
Sagina decumbens ssp. decumbens Trailing Pearlwort SNR   G5T5 Introduced?  
Sagittaria rigida Mud Arrowhead S2?   G5 Uncommon  
Salix candida Hoary Willow S3   G5 MESA-Delisted  
Salix pedicellaris Bog Willow S2?   G5 Uncommon  
Salix serissima Autumn Willow S3   G5 MESA-Delisted  
Sanguisorba canadensis Canada Burnet SNR   G5 Uncommon Sanguisorba canadensis ssp. canadensis
Sanicula trifoliata Trefoil Sanicle S2S3   G4 Uncommon  
Schoenoplectus acutus var. acutus Hard-stemmed Bulrush S2S3   G5T5 Uncommon Scirpus acutus
Schoenoplectus torreyi Torrey's Bulrush S2?   G5? Uncommon Scirpus torreyi
Scirpus pendulus Pendulous Bulrush S3   G5 MESA-Delisted  
Scirpus polyphyllus Appalachian Bulrush S2? 2 G5 Uncommon  
Scleria reticularis Pondshore Nut-sedge S3 1 G4 MESA-Delisted Scleria reticularis var. reticularis
Scutellaria parvula var. missouriensis Small Skullcap SNR 2 G4T4 Introduced? Scutellaria leonardii; Scutellaria parvula var. leonardii
Sedum ternatum Mountain-stonecrop SNR   G5 Introduced?  
Selaginella rupestris Rock Spikemoss S3S4   G5 MESA-Delisted  
Sesuvium maritimum Annual Sea-purslane SNR 2 G5 Newly Discovered  
Silene caroliniana ssp. pensylvanica Wild Pink S2S3   G5T4T5 Uncommon Silene caroliniana var. pensylvanica
Solidago hispida Hispid Goldenrod S1   G5 Historic Rediscovered  
Solidago speciosa var. speciosa Showy Goldenrod S2S3   G5T5? Uncommon Solidago speciosa ssp. speciosa var. speciosa
Sparganium androcladum Shining Bur-reed S3?   G4G5 Uncommon  
Sparganium angustifolium Narrow-leaved Bull-reed S2S3   G5 Uncommon  
Sparganium fluctuans Floating Bull-reed S2S3   G5 Uncommon  
Spiranthes lucida Shining or Wide-leaved Ladies'-tresses S2?   G4 Uncommon  
Spiranthes tuberosa Little Ladies'-tresses S3S4   G5 MESA-Delisted  
Sporobolus compositus var. compositus Tall Dropseed SNR   G5T5 Introduced?  
Sporobolus cryptandrus Sand Dropseed S2?   G5 Uncommon  
Stachys hyssopifolia Hyssop Hedge-nettle S3S4   G4G5 MESA-Delisted  
Stellaria borealis ssp. borealis Northern Starwort S2S3   G5T5 Uncommon Stellaria calycantha sensu lato; Stellaria borealis var. borealis
Streptopus amplexifolius Clasping-leaf Twisted-stalk S3?   G5 MESA-Delisted  
Suaeda maritima ssp. richii Rich's Sea-blite S2S3 IND. G5T3 MESA-Delisted Suaeda richii
Symphyotrichum praealtum Willow Aster S1 2 G5 Historic Rediscovered Aster praealtus
Symphyotrichum prenanthoides Crooked-stem Aster S2 2 G4G5 MESA-Delisted Aster prenanthoides
Tephrosia virginiana Goat's Rue SNR   G5 Uncommon  
Utricularia minor Lesser Bladderwort S2S3   G5 Uncommon  
Uvularia grandiflora Large-flowered Bellwort S3   G5 MESA-Delisted  
Veronica serpyllifolia ssp. humifusa Northern Thyme-leaf Speedwell SNR   G5T5? Introduced? Veronica serpyllifolia var. humifusa
Viola renifolia Kidney-leaf Violet S1S2   G5 Uncommon  
Viola rostrata Long-spurred Violet S2S3   G5 Uncommon  
Viola selkirkii Great-spurred Violet S1S2   G5 Uncommon  
Viola subsinuata Early Blue Violet S1S2 IND. G3G5 Uncommon  
Wolffia borealis Northern Water-meal SNR   G5 Uncommon  
Wolffiella gladiata Sickle Water-meal SNR 2 G5 Uncommon Wolffiella floridana
Xyris montana Northern Yellow-eyed Grass S2?   G5 Uncommon  
Xyris smalliana Quagmire Yellow-eyed grass S4   G5 Uncommon? Xyris congdonii
Zizania palustris var. palustris Slender Wild Rice S1S2   G5T4T5 Uncommon Zizania aquatica var. angustifolia

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