This list contains plant taxa which have been documented by herbarium voucher specimens to have occurred in Massachusetts in the past, yet have not been documented here in the past 25 years. 
Scientific NameMA Checklist SynonymCommon NameS RankNew England RankG Rank
Amaranthus pumilus Seabeach amaranthSH4G2
Anemone virginiana var. albaA. virginiana var. riparia; A. ripariaRiverbank ThimbleweedSH G5T4T5
Angelica venenosaA. villosaHairy-angelicaSH4G5
Callitriche terrestrisC. deflexaTerrestrial StarwortSH4G5
Calystegia silvatica ssp. fraternifloraC. fraterniflora; C. sepium var. fraterniflora; Convolvulus fraterniflorusShort-stalked False BindweedSH 2G5T5
Carex livida Livid SedgeSHG5
Carex peckii Peck's SedgeSH G5
Carex vacillans Swinging SedgeSH 2GNR
Carex wiegandii Wiegand's Prickly SedgeSH1G4
Carex willdenowii Willdenow's SedgeSH2G5
Castilleja coccinea Scarlet Painted CupSH2G5
Chenopodium rubrum Coast-bliteSNR G5
Crataegus dodgeiC. rotundata; C. gravesiiDodge's HawthornSH 4G4
Crataegus lumariaC. dodgei var. lumariaThorny HawthornSH 4GNRQ
Crataegus populneaC. compta; C. iracunda var. populnea; C. iracunda var. stoloniferaPoplar HawthornSH 2GNRQ
Crataegus schizophylla Cut-leaved HawthornSNR 2G1G2
Crataegus stonei Stone's HawthornSH 4GNR
Cuscuta indecora Collared DodderSH 2G5
Cuscuta pentagona Field-dodderSH 4G5
Desmodium sessilifolium Sessile-leaved Tick-trefoilSH 2G5
Dichanthelium ovale ssp. villosissimumD. villosissimum; Panicum villosissimumVillous Panic-grassSH 4G5T5
Dichanthelium scopariumPanicum scopariumVelvet Panic-grassSH 4G5
Draba reptans Carolina Whitlow-grassSH2G5
Echinodorus tenellusE. parvulus; E. tenellus var. parvulusLittle BurheadSH2G5
Eleocharis equisetoides Horsetail Spike-rushSH2G4
Eleocharis fallax Deceitful Spike-rushSH4G4G5
Eleocharis quadrangulata E. quadrangulata var. crassiorSquare-stemmed Spike-rushSH2G4
Elymus glabriflorus Southeastern Wild-ryeSH 2GNR
Equisetum palustre Marsh-horsetailSH G5
Floerkea proserpinacoides False MermaidSH2G5
Galium trifidum ssp. halophilum Seaside BedstrawSH G5T3T5
Halenia deflexa American Spurred GentianSH G5
Lechea intermedia var. juniperina Maine PinweedSH G5TNR
Linum sulcatum var. sulcatumL. sulcatumGrooved Yellow FlaxSH2G5T5
Lithospermum occidentaleOnosmodium virginianumFalse GromwellSH2G4
Muhlenbergia capillaris  HairgrassSH2G5
Oligoneuron rigidum var. rigidumSolidago rigida Stiff GoldenrodSH2G5
Paspalum laeve P. laeve var. circulareField Bead-grassSH2G4G5
Platanthera ciliarisHabenaria ciliarisYellow or Orange-fringed OrchisSH2G5
Platanthera obtusata P. obtusata; Habenaria obtusataBlunt-leaved OrchisSH G5
Polygala senega Seneca SnakerootSH G4G5
Potamogeton alpinus Northern PondweedSH G5
Pseudognaphalium micradeniumGnaphalium helleri var. micradenium; Gnaphalium obtusifolium var. micradeniumHeller's EverlastingSH4G3
Pseudolycopodiella caroliniana Lycopodium carolinianumCarolina or Slender ClubmossSX4G4
Puccinellia fasciculata Bunched Alkali-grassSH G3G5
Puccinellia pumilaP. tenella ssp. alascana; P. paupercula var. alaskanaNorthern Alkali-grassSH G4G5
Pyrola asarifolia Liverleaf WintergreenSH G5
Ranunculus ambigens American SpearwortSH2G4
Ranunculus flammula var. ovalis R. reptans var. ovalisCreeping SpearwortSH G5TNRQ
Saururus cernuus Lizard's TailSH2G5
Schoenoplectus halliiScirpus halliiHall's BulrushSH4G2G3
Schoenoplectus heterochaetus Scirpus heterochaetus; Scirpus lacustrisSlender BulrushSH2G5
Schwalbea americana ChaffseedSH4G2G3
Scutellaria integrifolia Hyssop SkullcapSH2G5
Selaginella eclipes S. apoda ssp. eclipesHidden Spike-mossSH4G4
Solidago hispidaS. bicolor var. concolorHispid GoldenrodSH G5
Sporobolus heterolepis  Northern DropseedSH2G5
Stachys pilosaS. palustris ssp. pilosa; Stachys palustris var. pilosaAmerican Hedge-nettleSHINDG5

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.