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Washington Natural Heritage Program
List of Rare Mosses
June 2012

At present, there is insufficient information, both in terms of inventory and degree of threat, to assign a statewide status (e.g., Endangered) to most of the mosses, as has been done with vascular plants. Unless noted, these mosses have a state status of Review Group 1 (R1, of potential concern but needs more field work to assign another rank). For those few species that have been assigned a state status, it is included below following the scientific name. The codes include E for Endangered (in danger of becoming extinct or extirpated from Washington) and T for Threatened (likely to become Endangered in Washington). They may also be found in our refined list, the List of Plants Tracked by the Washington Natural Heritage Program. Clicking on a scientific name that is underlined will take you to the field guide page (pdf format, average size 300 kb) for that taxon.

This list of mosses was originally developed in 1996 by Judy Harpel from a review of the literature and of specimens in the following herbaria: University of Washington, Western Washington University, Washington State University, Eastern Washington University, Central Washington University and the University of British Columbia. Information was also gathered from the following personal collections: Fred Rhodes (Olympic Mountains), John Davis (Columbia River Gorge) and Judy Harpel (statewide). Finally, long discussions with both Wilf Schofield and John Christy were very valuable in "fine tuning" this list. It should be understood that this is a working list and that new information may result in the removal or addition of species to the list.

Nomenclature follows that of the following two references:

Anderson, L.E., H.A. Crum and W.R. Buck. 1990. List of the Mosses of North America North of Mexico. The Bryologist 93:448-499.

Anderson, L.E. 1990. A checklist of sphagnum in North America North of Mexico. The Bryologist 93:500-501.

A key to rank fields appears below.


Scientific Name Author Family Name Global Rank State Rank
Andreaea megistospora B. Murr. Andreaeaceae G4G5 S1
Andreaea rothii Web. & Mohr Andreaeaceae G5 S1
Barbula eustegia Card. & Ther. Pottiaceae G3? S1
Bartramiopsis lescurii (E)(James) Kindb. Polytrichaceae G3G5 S1
Brachydontium olympicum (Britt.) McIntosh & Spence Seligeriaceae G2G3 S1
Brachydontium trichodes (Web.) Milde Seligeriaceae G2G4 S1
Brotherella roellii (T)(Ren. & Card. in Roll) Fleisch. Sematophyllaceae G3 SH
Bryoerythrophyllum columbianum (Herm. & Laut.) Zand. Pottiaceae G3G4 S2
Bryoxiphium norvegicum (Brid.) Mitt. Bryoxiphiaceae G5? S1
Bryum calobryoides Spence Bryaceae G3 S1
Bryum violaceum Crundw. & Nyh. Bryaceae G5? S1
Buxbaumia aphylla Hedw. Buxbaumiaceae G4G5 S3
Buxbaumia viridis (D.C.) Moug. & Nestl. Buxbaumiaceae G4G5 SU
Calliergon trifarium (Pseudocalliergon trifarium) (Web. & Mohr) Kindb. Amblystegiaceae G4 SNR
Campylium stellatum(Hedw.) C. Jens. Amblystegiaceae G5 SNR
Campylopus atrovirens De Not. Dicranaceae G4G5 S1
Campylopus fragilis (Brid.) Bruch & Schimp. in B.S.G. Dicranaceae G5? S1
Campylostelium saxicola (Web. & Mohr) Bruch & Schimp. in B.S.G. Ptychomitriaceae G3G5 S1
Conostomum tetragonum (Hedw.) Lindb. Bartramiaceae G5 S1
Crumia latifolia (Kindb. in Mac.) Schof. Pottiaceae G3 S1
Dicranodontium denudatum (Brid.) Britt. in Williams Dicranaceae G4G5 S1
Dicranum muehlenbeckii Bruch & Schimp. in B.S.G. Dicranaceae G3G5 S1
Discelium nudum (Dicks.) Brid. Disceliaceae G3G4 S1
Ditrichum schimperi (Lesq.) Kuntze Ditrichaceae G3G5 S1
Ditrichum zonatum var. scabrifolium Dix. Ditrichaceae G3G5T2T3 S1
Drepanocladus crassicostatus Janssens Amblystegiaceae G3G5 S1
Encalypta brevicollis (E)(Horton) Crum & Anderson Encalyptaceae G4T1 S1
Entosthodon fascicularis (Hedw.) C. Mull. Funariaceae G4G5 S1
Fissidens fontanus (B. Pyl.) Steud. Fissidentaceae G5 S1
Fissidens grandifrons Brid. Fissidentaceae G4 S2
Fissidens osmundioides Hedw. Fissidentaceae G5 S1
Fissidens pauperculus Howe Fissidentaceae G3? S1
Fissidens ventricosus Lesq. Fissidentaceae GU S3
Funaria muhlenbergii Turn. Funariaceae G4 S1
Grimmia incurva Schwaegr. Grimmiaceae G4G5 S1
Hedwigia ciliata (Hedw.) P. Beauv. Hedwigiaceae G5 SNR
Helodium blandowii (Web. & Mohr) Warnst. Helodiaceae G5 S1
Herzogiella seligeri (Brid.) Iwats. Hypnaceae G3G4 S1
Homalia trichomanoides (Hedw.) Schimp. in B.S.G. Neckeraceae G5 S1
Hookeria acutifolia Hook. & Grev. Hookeriaceae G4G5 S1
Hygrohypnum norvegicum (Schimp. in B.S.G.) Amann Amblystegiaceae G2 S1
Iwatsukiella leucotricha (E)(Mitt.) Buck & Crum Pterigynandraceae G4G5 S1
Meesia triquetra (Richt.) Angstr. Meesiaceae G5 S1
Meesia uliginosa Hedw. Meesiaceae G4 S1
Mnium arizonicum Amann Mniaceae G5? S1
Myurella julacea (Schwaegr.) Schimp . in B.S.G. Pterigynandraceae G5 S1
Neckera pennata Hedw. Neckeraceae G5 S1
Oncophorus wahlenbergii Brid. Dicranaceae G5 S1
Orthothecium chryseum (Schwaegr. in Schultes) Schimp. in B.S.G. Hypnaceae G5? S1
Orthotrichum bolanderi Sull. Orthotrichaceae G2G4 S1
Orthotrichum hallii Sull. & Lesq. in Sull. Orthotrichaceae G4 S1
Orthotrichum praemorsum (E)Vent. in Roll. Orthotrichaceae G2 S1
Orthotrichum pylaisii Brid. Orthotrichaceae G4G5 S1
Orthotrichum sordidum Sull. & Lesq. in Aust. Orthotrichaceae G5 SNR
Plagiopus oederiana (Sw.) Crum & Anderson Bartramiaceae G5? S2
Platyhypnidium riparioides (Hedw.) Dix. Brachytheciaceae G4 S1
Pleuroziopsis ruthenica (Weinm.) Kindb. ex Britt. Pleuroziopsidaceae G3 SNR
Pohlia cardotii (Ren. in Ren. & Card.) Broth. Bryaceae G2G3 S1
Pohlia columbica (Kindb. in Mac. & Kindb.) Andrews Bryaceae G3G5 S1
Pohlia erecta Lindb. Bryaceae G3G5 S1
Pohlia sphagnicola (Bruch & Schimp.) Lindb. & Arnell Bryaceae G3? S1
Polytrichum strictum Brid. Polytrichaceae G4 S2
Ptilium crista-castrensis (Hedw.) De Not. Hypnaceae G5 SU
Racomitrium aquaticum (Brid. ex Schrad.) Brid. Grimmiaceae G3G5Q S3
Racomitrium lawtonae Irel. Grimmiaceae G3G4 SU
Racomitrium microcarpon (Hedw.) Brid. Grimmiaceae GNRQ S1
Rhytidium rugosum (Hedw.) Kindb. Rhytidiaceae G5 S1
Schistostega pennata (Hedw.) Web. & Mohr Schistostegaceae G3G4 S2
Scouleria marginata (T)Britt. Scouleriaceae G3 S2
Sphagnum austinii Sull. in Aust. Sphagnaceae G4 S1
Sphagnum centrale C. Jens. in Arnell & C. Jens. Sphagnaceae G5 S1
Sphagnum contortum Schultz Sphagnaceae G5 S1
Sphagnum jensenii H. Lindb. Sphagnaceae GU S1
Sphagnum riparium Angstr. Sphagnaceae G5 S1
Tayloria serrata (Hedw.) Bruch & Schimp. in B.S.G. Splachnaceae G4 S1
Tetraphis geniculata Girg. ex Milde Tetraphidaceae G3G5 S2
Tetraplodon mnioides (Hedw.) Bruch & Schimp. in B.S.G. Splachnaceae G4 S1
Tetrodontium brownianum (Dicks.) Schwaegr. Tetraphidaceae G3G4 S1
Thamnobryum neckeroides (Hook.) Lawt. Thamnobryaceae G4 S2
Tomentypnum nitens (Hedw.) Loeske Brachytheciaceae G5 SNR
Tortula laevipila var. meridionalis (Schimp.) Wijk & Marg. Pottiaceae G3G4TNR SNR
Tortula papillosa Wils. in Spruce Pottiaceae G5 S1
Trichostomopsis australasiae (Grev. & Hook.) Robins. Pottiaceae G5? S2


Description of Rank Codes
Global Rank (GRank)
Global Rank characterizes the relative rarity or endangerment of the element world-wide.
G1 = Critically Imperiled - At very high risk of extinction or elimination due to very restricted range, very few populations or occurrences, very steep declines, very severe threats, or  other factors.
G2 = Imperiled - At high risk of extinction or elimination due to restricted range, few populations or occurrences, steep declines, severe threats, or other factors.
G3 = Vulnerable - At moderate risk of extinction or elimination  due to a fairly restricted range, relatively few populations  or occurrences, recent and widespread declines, threats, or other factors.
G4 = Apparently Secure - At fairly low risk of extinction  or elimination due to an extensive range and/or many populations or occurrences, but with possible cause for some concern as a result of local recent declines, threats, or other factors.
G5 = Secure  At very low risk or extinction or elimination due to a very extensive range, abundant populations or occurrences, and little to no concern from declines or threats.
GH = Possibly Extinct - Known from only historical occurrences but still some hope of rediscovery.
GU = Unrankable - Currently unrankable due to lack of information or due to substantially conflicting information about status or trends.
GX = Presumed Extinct - Not located despite intensive searches and virtually no likelihood of rediscovery.
GNR = Unranked - Global rank not yet assessed.
G#G# = Range Rank - A numeric range rank (e.g., G2G3, G1G3) is used to indicate uncertainty about the exact status of a taxon or ecosystem type.
Rank Qualifiers
? = Inexact Numeric Rank - Denotes inexact numeric rank.
Q = Questionable taxonomy that may reduce conservation priority   Distinctiveness of this entity as a taxon at the current level is questionable; resolution of this uncertainty may result in change from a species to a subspecies or hybrid, or inclusion of this taxon or type in another taxon or type, with the resulting taxon having a lower-priority (numerically higher) conservation status rank.
Infraspecific Taxon  status ranks
T# = Infraspecific Taxon (trinomial) - The status of infraspecific taxa (subspecies or varieties) are indicated by a “T-rank” following the species’ global rank. Rules for assigning T-ranks follow the same principles outlined above.

State Rank (SRank)
State Rank characterizes the relative rarity or endangerment within the state of Washington.
S1 = Critically Imperiled - At very high risk of extirpation in the state due to very restricted range, very few populations or occurrences, very steep declines, severe threats, or other factors.
S2 = Imperiled - At high risk of extirpation in the state due to restricted range, few populations or occurrences, steep declines, severe threats, or other factors.
S3 = Vulnerable - At moderate risk of extirpation in the state due to a fairly restricted range, relatively few populations or occurrences, recent and widespread declines, threats, or other factors.
S4 = Apparently Secure - At a fairly  low risk of extirpation in the  state due to an extensive range and/or many populations or occurrences, but  with  possible cause for some concern as a result of local recent  declines, threats, or other factors.
S5 = Secure - At very low or no risk of extirpation in the state due to a very extensive range, abundant populations or occurrences, with little to no concern from declines or threats.
SH = Possibly Extirpated - Known from only historical records but still some hope of rediscovery.
SX = Presumed Extirpated - Species is believed to be extirpated from the state. Not located despite intensive searches of historical sites and other appropriate habitat, and virtually no likelihood that it will be rediscovered.
Rank Qualifiers
S#? = Inexact Numeric Rank - Denotes inexact numeric rank.
S#S# = Range Rank - A numeric range rank (e.g., S2S3 or S1S3) is used to indicate any range of uncertainty about the status of the species.
SU = Unrankable - Currently unrankable due to lack of information or due to substantially conflicting information about status or trends.
SNR = Unranked - Subnational conservation status not yet assessed
SNA = Not Applicable - A conservation status rank is not applicable because the species or ecosystem is not a suitable target for conservation activities.

Washington Natural Heritage Program - www.dnr.wa.gov/ResearchScience/Topics/NaturalHeritage/Pages/amp_nh.aspx
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Washington Dept. of Natural Resources, PO Box 47014, Olympia, WA 98504-7014