State-Listed Pteridophytes in Rhode Island

These are the lycophytes, ferns and fern allies that are officially listed as rare by the State of Rhode Island. The information is taken from the Rhode Island Natural Heritage Program's Rare Native Plants of Rhode Island.


The status of each species is designated by letter codes as defined below:
(FE) Federally Endangered. (1 RI species currently listed)
(FT) Federally Threatened. (2 RI species currently listed)
(SE) State Endangered. Native taxa in imminent danger of extirpation from Rhode Island. These taxa may meet one or more of the following criteria:
(ST) State Threatened. Native taxa which are likely to become State Endangered in the future if current trends in habitat loss or other detrimental factors remain unchanged. In general, these taxa have 3-5 known or estimated populations and are especially vulnerable to habitat loss.
(C) Concern. Native taxa not considered to be State Endangered or Threatened at the present time, but are listed due to various factors of rarity and/or vulnerability.
(SH) State Historical. Native taxa which have been documented for Rhode Island during the last 150 years but for which there are no extant populations. When known, the year of last documented occurrence is included.

Note on Status Designation:

For most listed plants the definitions outlined above have been adhered to when assigning status. In some cases, especially for those species which have not received intensive field inventory, the "Concern" category is assigned even if only 1-2 populations are known to be extant. These species are targeted for additional inventory and may be assigned to other categories when their actual status in Rhode Island has been clarified. Taxa so-defined are designated with an asterisk (*).

LGlobal Rank

Each taxon has been assigned a “global rank” that reflects its rarity and vulnerability to extinction throughout the world. Global ranks were originally derived by The Nature Conservancy and are used by all Natural Heritage Programs as a standardized method of determining the status of each taxon throughout its range. These ranks are defined as follows:
G1 = Critically imperiled throughout its range due to extreme rarity (5 or fewer sites or very few remaining individuals) or extremely vulnerable to extinction due to biological factors.
G2 = Imperiled throughout its range due to rarity (6-20 sites or few remaining individuals) or highly vulnerable to extinction due to biological factors.
G3 = Either very rare and local throughout its range (21-100 sites), with a restricted range (but possibly locally abundant), or vulnerable to extinction due to biological factors.
G4 = Apparently secure throughout its range (but possibly rare in parts).
G5 = Demonstrably secure throughout its range (but possibly rare in parts).
GH = No extant sites known, but may be rediscovered.
GX = Believed to be extinct.
T = Appended to a G rank to indicate status of a subspecies or variety
Double Ranks (e.g., G2G3): The first rank indicates rarity based on current documentation. The second rank indicates the probable rarity after all historical records and potential habitats have been surveyed. Denotes taxa needing additional survey to assign global status.

NEPCoP Status Designation

NEPCoP Status Designation indicates the taxon is cited in Flora Conservanda: New England. The New England Plant Conservation Program (NEPCoP) List of Plants in Need of Conservation. Taxa included in this publication are assigned to one of 5 Divisions based on the following definitions:
Div 1: Globally rare taxa occurring in New England. Taxa in this division have been ranked as globally rare (G1 through G3, or T1 through T3) under criteria described above.
Div 2: Regionally rare taxa with fewer than 20 current occurrences within New England.
Div 3: Locally rare taxa that may be common in part of New England, but have one or more occurrences of biological, ecological, or possible genetic significance.
Div 4: Historic taxa that once existed in New England, but have not been seen since 1970.
IND: Indeterminate taxa under review for inclusion in one of the above divisions, but issues of taxonomy, nomenclature, or status in the wild are not clearly understood.

County of Occurrence

Each county is designated by the first two letters of its name as follows: Counties are identified for extant populations only, except in the case of Historic species in which the last county of occurrence is given.

* means believed extirpated

SpeciesCommon NameStatus

True Ferns

SCAsplenium montanummountain spleenwort
TAsplenium ruta-murariawallrue spleenwort
ECheilanthes lanosahairy lip-fern
ECryptogramma stellerislender cliff-brake
EDiplazium pycnocarponnarrow-leaved glade fern
EDryopteris campylopteramountain wood-fern
SCDryopteris goldianaGoldie's fern
SCLygodium palmatumclimbing fern
EPellaea glabellasmooth cliff-brake
SCTrichomanes intricatumAppalachian gametophyte

Fern Allies

SC*Equisetum palustremarsh horsetail
EEquisetum pratensemeadow horsetail
EEquisetum scirpoidesdwarf scouring rush
TOphioglossum pusillumadder's-tongue
SC*Botrychium simplexlittle grape fern


SC*Huperzia selagofir clubmoss
ELycopodiella alopecuroidesfoxtail clubmoss