Table Of ContentLichvar, R.W. 2013. The National Wetland Plant List: 2013 wetland ratings. Phytoneuron 2013-49: 1-241. Published 17 July
2013. ISSN 2153 733X
THE NATIONAL WETLAND PLANT
LIST:
WETLAND
RATINGS
2013
Robert W. Lichvar
Army
U.S. Engineer Research and Development Center
Cold Regions Research and Engineering Laboratory
72 Lyme Road
New
Hanover, Hampshrre 03755-1 290
ABSTRACT
Army (NWPL)
The U.S. Corps of Engineers administers the National Wetland Plant List for
NWPL
the United States (U.S.) and its territories. Responsibihty for the was transferred to the Corps
from the U.S. Fish and Wildlife Service in 2006. The hst had not been updated since 1988, and the
Corps led an interagency effort to revise the list by 2012. As part of the authorization of the revised
NWPL
in 2012, new methods were adopted for annual updates to the scientific names and wetland
ratings. This paper presents the first annual update of the 2012 list. The 2012 list contained 7,828
species, and the 2013 update presented here contains 7,937 species. The increase of 109 species is
due to nomenclature and taxonomic changes, species that were added by request, and new records
from the literature and herbarium records. There was a change of 327 wetland ratings nationally
during the 2013 update.
Background
Army
Since the U.S. Corps of Engineers (Corps) assumed administrative responsibilities for
(NWPL)
the National Wetland Plant List in 2006, the has gone through an extensive updating
list
May
process that culminated in authorization for national use in 2012 (Federal Register 2012,
its
Lichvar 2012). The development of the 2012 list was a cooperative effort between four federal
government agencies: the Corps, the U.S. Fish and Wildhfe Service (FWS), the U.S. Environmental
Protection Agency (EPA), the Natural Resources Conservation Service (NRCS). The effort was
NWPL
managed by a National Panel consisting of representatives from the four agencies. The 2012
is the standard reference for wetland indicator status ratings of vascular plants in the United States
many
and is used for purposes, including wetland delineation, assessment, mitigation, and habitat
NWPL
restoration. The is available to all users through a web application (http://wetland_plants.usace.
army.mrl/).
The 2012 update buih on the legacy of the FWS's 1988 (Reed 1988) and draft 1996 wetland
plant lists. It integrated all current taxonomic views along with revised wetland ratings (Lichvar and
Minkin 2008). Additionally, the 2012 revision included several changes to the management of the
NWPL, along with revised definitions of wetland categories, new Corps geographic wetland regions,
protocols for challenging wetland ratings, and procedures for annual revisions.
NWPL
The five wetland rating categories in the were developed in the 1980s by Reed
(1988). Each plant species was assigned a rating representing the estimated probabihty, or frequency,
with which it is thought to occur in wetlands, as opposed to non-wetlands, across its entire range. The
1988 ratings were divided into categories based on quantitative ranges of frequency, but the 2012
ratings were based on simpler qualitative definitions (Lichvar et al. 2012) (Table 1). Indicator status
now
ratings are assigned to each species based on a thorough review of the botanical literature and
herbarium records, along with the best professional judgment of national and regional experts.
Longer quantitative rating definitions are used, but only for field testing of wetland ratings.
still
Table 1. Short qualitative descriptions of the five wetland indicator status ratings used to determine if
vegetation is hydrophytic during wetland delineations in the United States.
Indicator status Qualitative Description
rating (abbreviation) Designation (Lichvaretal. 2012)
Obligate (OBL) Hydrophyte Almost always occur in wetlands
Facultative Wetland Hydrophyte Usually occur in wetlands, but may occur in non-
(FACW)
wetlands
Facultative (FAC) Hydrophyte Occur in wetlands and non-wetlands
Facultative Upland Nonhydrophyte Usually occur in non-wetlands, but may occur in
(FACU)
wetlands
Upland (UPL) Nonhydrophyte Almost never occur in wetlands
NWPL,
Figure 1. Geographic regions for the 2012 based on Corps regions.
Lichvar: 2013 National Wetland Plant List 3
NWPL
As with previous versions of the wetland plant the 2012 supports wetland
list,
delineation efforts under Sec. 404 of the Clean Water Act and the Swampbuster provisions under the
Farm Bill, and it is used in the National Wetland Inventory Program. To accomphsh this more
NWPL's
effectively, the Corps re-aligned the geographic regions to correspond to those of Federal
wetland efforts, including the interagency wetland delineation manual and its regional wetland
NWPL
now
delineation supplements. The divided using the 10 regional Corps wetland delineation
is
regions for the U.S. and its territories (Wakeley 2002) (Fig. 1). Included within four of these Corps
regions are 17 subregions in which small numbers of wetland plants have wetland ratings that differ
from the ratings for the same plants in the rest of the region (Appendices B-E).
Annual Update Process
NWPL
As part of the 2012 update, representatives from each of the four Federal agencies
NWPL
responsible for the agreed on new protocols and procedures for managing the These
list.
NWPL.
procedures were described in the 2012 Federal Register announcement for updating the
NWPL
Under the authorization, it is now possible to update and maintain the list annually so that the
nomenclature and taxonomy do not become outdated and wetland ratings can be refined as new
NWPL
information is available. In particular, the annual updates will include additions or deletions
to the modifications to wetland indicator statuses that were revised during the previous year; and
list;
NWPL.
updates of the nomenclature, taxonomy, and geographic distribution of species on the
The annual update of the list has two steps. First, the database is updated for nomenclature,
taxonomy, and U.S. state/Canadian province and U.S. county-level phytogeography by Dr. John
(BONAP)
Kartesz of the Biota of North America (http://www.bonap.org). Second, input from the
public, as well as from Federal and state agencies, is used to modify wetland ratings by processes of
may
evaluation that are similar to those used during the 2012 update. These requests include adding
new
species to the hst.
NWPL
The annual update is released in three parts: 1) the web site is updated to reflect any
modifications from the previous year, 2) a series of downloadable files for the Corps regions and
states is made available via the web site, providing local lists of wetland species and their wetland
indicator ratings, and 3) the national list is published and subdivided by Corps regions. This
publication represents the third component of the 2013 update.
NWPL
The 2013 Update
NWPL NWPL
The 2012 contained 7,828 species of wetland plants. The 2013 increased by
109 species, so it now includes 7,937 wetland plants for the United States and its territories. The
increase in number was due to various factors, including changes in taxonomy, new literature reports,
NWPL
and newly suggested additions to the list. The final 2013 is listed in the appendices.
BONAP
Taxonomic changes made by since the 2012 list have both added to and subtracted
NWPL.
from the Species dropped from the list included taxonomic merges that reduced the list by 49
species, two erroneously reported species not occurring in North America, and one invalid name
(Table 2). The merged species, now treated as synonyms, were deleted from the list since they were
combined with other taxa. Also, eight former wetland species were merged into four new species that
were not previously recognized. These four new species were added to the hst (Table 3). Prior 2012
wetland indicator ratings were applied to these new names since all former names had the same
When
wetland ratings. taxa with different wetland ratings were merged into one (e.g., one former
FAC
taxon was and the other FACW), new wetland ratings were assessed by the Regional and/or
National Panels. Of the four new species added to the list based on mergers, only Rhododendron
columbianum (Piper) Harmaja and Zeltnera muehlenbergii (Griseb.) G. Mans, required reevaluation
due to conflicts in prior wetland ratings.
Lichvar: 2013 National Wetland Plant List 4
BONAP
In addition to the revisions, users requested that 112 wetland species be either
reevaluated or added to the 2013 These requests were processed through standardized protocols.
list.
Each request was first evaluated by a Regional Panel (RP) consisting of one representative from each
RP
of the four agencies within the Corps regions where the species occurs. The reviewed the
literature, interviewed other professional botanists, and used their personal field observations to
RP
assign wetland ratings. If the was in dispute about assigning a rating, the National Panel assigned
the final wetland ratings. The species for which new or further review was requested are shown in
NWPL
Table 3 and are listed on the web site (http://wetland_plants.usace.army.mi1/l.
The addition and reevaluation of 112 species resulted in 119 changes in wetland ratings at the
NWPL
national level. Twelve species that were already on the were reevaluated. Nine species were
added in more than one Corps region. Seven others were determined to be UPL. Overall, these new
additions, re evaluations, and nomenclature changes represent only a 1.2% change from the 2012
list.
The resulting wetland ratings for the annual update are nearly evenly divided between the four
wetland ratings categories in each of the 10 Corps wetland regions (Table The exception
4). is
FACU
Hawaii, because the South Pacific Island subregion dominated by species.
is
ACKNOWLEDGEMENTS
Many
people, agencies and organizations are involved in maintaining and improving the
NWPL,
accuracy of the and they are all thanked for their support and input. The bulk of the effort
and thanks goes to the National and Regional Panel members across the country who dedicate
Many
significant time and energy responding to requests to evaluate endless lists of wetland plants.
people in the public sector have made valuable suggestions and input about wetland species.
Underlying these efforts is the work of several key people, who are thanked: John Kartesz at BONAP,
BONAP
who keeps the database updated, and Misako Nishino, who maintains the database; Rick
Bates and John Guineau, who manage to keep millions of data points in the right places; and Jennifer
We
Gillrich and Lindsey Lefebvre, who make happen. thank the Wetland Regulatory Assistance
it all
Army
Program of the U.S. Corps of Engineers for funding these efforts.
REFERENCES
Federal Register. 2012. Publication of the Final National Wetland Plant List. Federal Register,
May
Vol. 77, No. 90, Wednesday, 9, 2012.
Kartesz, J.T. 2012. Floristic Synthesis of North America, Version 1.0. Biota of North America
Program (BONAP). Chapel Hill, North Carolina.
Lichvar, R.W. and P. Minkin. 2008. Concepts and procedures for updating the National Wetland
ERDC/CRREL Army
Plant List. TN-08-03. U.S. Engineer Research and Development
New
Center, Cold Regions Research and Engineering Laboratory, Hanover, Hampshire.
<http://libweb.erdc.usace.army.mil/Archimages/2295.PDF>
Lichvar, R.W. 2012. The National Wetland Plant List. ERDC/CRREL TR-12-11. U.S. Army
Engineer Research and Development Center, Cold Regions Research and Engineering
New
Laboratory, Hanover, Hampshire.
Lichvar, R.W., N.C. Melvin, M.L. Butterwick, and W.N. Kirchner. 2012. National Wetland Plant
ERDC/CRREL Army
List indicator rating definitions. TR-12-1. U.S. Engineer Research
and Development Center, Cold Regions Research and Engineering Laboratory, Hanover,
New
Hampshire.
Reed, P.B., 1988. National List of Plant Species that Occur in Wetlands. U.S. Fish and Wildlife
Jr.
Service, Washington, D.C.
Wakeley, J.S. 2002. Developing a "regionalized" version of the Corps of Engineers Wetlands
ERDC/EL Army
Delineation Manual: Issues and recommendations. TR-02-20. U.S.
Engineer Research and Development Center, Environmental Laboratory, Vicksburg,
Mississippi.
3
Lichvar: 2013 National Wetland Plant List 5
Table 2. Scientific names or actual named taxa removed from the National Wetland Plant List durmg the 201
update. Actual named taxa marked with one asterisk were removed because they do not occur in North
America in the wild, and the name with two asterisks was viewed to be invalid. The remaining names were
Amsonia Mimulus
lUustris biolettii
AschpiashMla Mona, delta glauca
AzoUa microphylla Opuntia
dillenii
4zolla caroliniana Oxvpolis denticulata
Bartonia texana Ox}foUsfmformrs
Cardamine regehana'^ Oxypolis greenmanii
Carex alhida Oxypolis rigidior
hyetopMa Pwnaysiacalifomica
Castilleja
Castilleja iiliginosa Platanthera convallariifolia
Centaurium davvi Poh ctenium williamsiae
Centauriiim nmehlenbeign Ptihmmum ahlesii
Cmssula saginoides Ptihmmum nodosum
Crataegus mtida Rhododendron oblongifolium
Crataegus texana Rubui ritrfohus
Rumex
CyperusfiUculmis tomentellus
Cyrilla parvifoUa Sa/i.v matsudana
Dodecatheon eUisiae Scepti iduim silaifolium
Elymus violaceus Sedella congdomi
SpajtmaXtovnsendn
Halesia tetraptera
macrospora" Spmgamumerectum*
Isoetes
Vaccmmm
luncus biflorus vwgatum
Ledum columbianum Veibena Carolina
Ledum glandulosum
Limnanthes gracilis
Limnanthes striata Viola esculenta
Vmla
triloba
Lichvar: 2013 National Wetland Plant List 6
InWPL
marked with two asterisks. The remaining species were proposed since the 201 update.
Abies procera Dipsacus laciniatus Persicaria longiseta
Achillea ptarrmca Epilobium parviflorum Petasites hybridus*
Aconitum redmatiim Eschscholzia californica Platanthera aquilonis
Aconitum imcmatiim Filipendula ulmana Platanthera brevifolia
Actaea podocarpa Fragana chiloensis Po^o^ne clareana*
A^aliniscalycna Fraxmus anomala Polygonatum pubescens
Agalinisskinneriana Galium mollugo Prunus avium
Alliaria petiolata* Garrya elhptica Pulicaria paludosa'^
X
Amaranthus tuberculatum'' Geramum robertiamim Reynoutria bohemica
Ambrosia trifida" Glyceria laxa Rhododendron columbianum'^'^
Anaphalis mar^aritacea Harperella nodosa'^'' Rhododendron macrophyllum
Anthoxanthum hirtum Hedera helix Rhynchospora reco^nita
Arbutus menziesii Hedera hibernica Ribes laxiflorum
Aristida beyrichiana Helianthus strumosus Ribes lobbii
Azolla cristata'"' Helianthus tuberosus Ribes sanguineum
Baptisia australis Heracleum mantegazzianum Rubus caesius
Betula murrayana Hypericum virgatum Rubus pensilvanicus
Betula pendula Ilex aquifohum Rubus phoenicolasius
Brachyelytrum erectum Ilex collina Sambucus m^ra""
Cardamine impatiens Ilexmontana Sceptndmm oneidense
Cardamine pratensis Isoetes lacustris'' Schmus molle
Carex Juncus anthelatus Sedum ternatum
ef,f,lestomi
Carex radiata Linum mtercursum Sela^mella echpse
Carex retroflexa Ludwipa ravenn Senecio minimus
Carex rosea Lyciumtorrey, Silphium mte^rifohum
Castilleja septentrionahs Lycopodiella margueritae Sisvrinchium stiictum''
Centaureajacea Lycopodiella subappressa Sphenopholis intermedia
CentaureaX moncktomi Magnolia acuminata Sphenopholis nitida
Cirsium palustre Uahonia nervosa Sporoboluswrightii
Cirsiumwrightii Uedeola virginiana Svmphoricarpos mollis
Clematis vitalba Ueehania cordata Toxicodendron diversilobum
Mentha Xrotundifolia Ulex europaeus
Ulmus glabra
Cytisus scoparius Mimulus michiganensis* Valeriana uliginosa
Daphne mezereum Monarda
clinopodia Valerianella chenopodiifolia
Muhlenbergia Viburnum nudum *
glabrifloris
Diarrhena obovata Muhlenbergia tenuiflora Washingtonia robusta
Dichanthelium leucothrix Xerophyllum tenax
Perillafrutescens Zeltnera muehlenbergii'"'
Lichvar: 2013 National Wetland Plant List 7
OBL
Table 4. Each Corps wetland region and its number of species and percent of occurrence is provided for
througli FACU. Tliese numbers mclude subregion ratings as well.
OBL FACW FAC FACU
Region* Ratings Total
AGCP
number 1116 953 855 792 3,716
percent 30.0 25.6 23.0 21.3
AK
number 262 253 298 224 1,037
percent 25.3 24.4 28.7 21.6
AW
number 757 845 742 837 3,181
percent 23.8 26.6 23.3 26.3
CB
number 296 293 344 269 1,202
percent 24.6 24.4 28.6 22.4
EMP
number 916 703 612 772 3,003
percent 30.5 23.4 20.4 25.7
GP
number 814 806 751 758 3,129
percent 26.0 25.8 24.0 24.2
HI number 139 154 450 675 1,418
percent 9.8 10.9 31.7 47.6
MW
number 677 517 428 697 2,319
29.2 22.3 18.5 30.1
NCNE
number 766 534 441 735 2,476
30.9 21.6 17.8 29.7
WMVC
number 778 798 717 797 3,090
25.2 25.8 23.2 25.8
number
National 6,521 5,856 5,638 6,556 24,571
percent 26.5 23.8 22.9 26.7
* Acronyms for each Corps region are as follows: Atlantic and Gulf Coastal Plain
(AGCP), Alaska (AK), Arid West (AW), Caribbean Islands (CB), Eastern Mountains
and Piedmont (EMP), Great Plains (GP), Hawaii and South Pacific Islands (HI and SPI),
Midwest (MW), and Western Mountams, Valleys, and Coast (WMVC).
NWPL
Appendix A. 2013 Ratings. Species Marked with an Asterisk Occur Only in the SPI Subregion.
San Diego Thorn-Mint
