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At-risk Wetland Plant Associations

At-risk Wetland Plant Associations

Since 1975, the Oregon Biodiversity Information Center (ORBIC), formerly the Oregon Natural Heritage Information Center (ORNHIC), has tracked occurrences of rare plant associations. The following section lists rare plant associations for each of 16 generalized wetland types in Oregon. The lists are based on the 2004 Classification of Native Vegetation of Oregon.

ORBIC participates in an international system for ranking rare, threatened and endangered species and plant associations throughout the world. The ranking is a 1-5 scale, primarily based on the number of known occurrences, but it also includes threats, sensitivity, area occupied, and other biological factors. The Global Rank begins with a "G" and the State Rank begins with the letter "S." Details are available at NatureServe.

1= Critically imperiled because of extreme rarity or because it is somehow especially vulnerable to extinction or extirpation, typically with 5 or fewer occurrences.

2 = Imperiled because of rarity or because other factors demonstrably make it very vulnerable to extinction (extirpation), typically with 6-20 occurrences.

3 = Rare, uncommon or threatened, but not immediately imperiled, typically with 21-100 occurrences.

4 = Not rare and apparently secure, but with cause for long-term concern, usually with more than 100 occurrences.

5 = Demonstrably widespread, abundant, and secure.

Q = Taxonomic questions

T = Rank for subspecies or variety

Alkaline Wetlands

Scientific NameCommon NameRank
Artemisia tridentata ssp. tridentata / Leymus cinereusbasin big sagebrush / basin wildryeG2S1
Deschampsia cespitosa - Carex douglasiitufted hairgrass - Douglas' sedge alkaline prairieG2S2
Leymus cinereusbasin wildrye bottomlandsG1S1
Puccinellia lemmonii - Poa secundaLemmon alkaligrass - Sandberg bluegrassG2S1

Aquatic Beds

Scientific NameCommon NameRank
Isoetes nuttalliiNuttall quillwort bedG2G3,S2S3
Myriophyllum hippuroideswestern water-milfoil bedG3S2
Ranunculus lobbiiLobb buttercup aquatic bedG2S2
Scirpus subterminaliswater clubrush bedG3S2


Scientific NameCommon NameRank
Calamagrostis nutkaensisPacific reedgrass fenG3S1
Carex aquatilis var. dives - Comarum palustreSitka sedge - purple marshlocksG2S2
Carex cusickiiCusick sedge fenG3S2
Carex cusickii - (Comarum palustre) fenCusick sedge - (bog cinquefoil) fenG2S2
Carex lenticularislenticular sedge fenG3S2
Carex limosamud sedgeG2S2
Carex luzulinawoodrush sedge fenG3S2
Carex obnupta / Sphagnumslough sedge / sphagnumG3S2
Eleocharis quinqueflorafew-flowered spikerush fenG4S2
Eleocharis quinqueflora - Eriophorum crinigerfew-flowered spikerush - fringed cottongrass ultramafic fenG2S2
Kalmia microphylla / Carex nigricansbog laurel / black alpine sedge shrub swampG3S2
Ledum glandulosum - Gaultheria shallon / Carex obnuptawestern Labrador tea - salal / slough sedge fenG2S2
Ledum glandulosum - Myrica galewestern Labrador tea - sweet gale heathG1S1
Ledum glandulosum / Carex obnuptawestern Labrador tea / slough sedge fenG2S2
Ledum glandulosum / Darlingtonia californicawestern Labrador tea / darlingtoniaG2S2
Ledum glandulosum / Sanguisorba officinaliswestern Labrador tea / burnetG1G2, S1S2
Myrica galesweet gale fenG4S1
Nephrophyllidium crista-gallideer cabbage flushG4S1
Populus tremuloides / Carex obnuptaquaking aspen / slough sedgeG1S1
Salix barclayiBarclay's willowG4S1
Salix drummondianaDrummond willowG3S1
Salix geyeriana - Salix hookerianaGeyer willow - Piper willowG3S2
Salix hookeriana - (Malus fusca) / Carex obnupta - Lysichiton americanuscoast willow - (crabapple) / slough sedge - skunk cabbage shrub swampG3S2
Spiraea douglasii - Vaccinium uliginosum / Carex obnupta - Deschampsia caespitosaDouglas spiraea - bog blueberry / slough sedge / sphagnumG2S2
Spiraea douglasii / SphagnumDouglas spiraea / sphagnum fenG3S1
Tsuga heterophylla / Ledum glandulosum / Carex obnupta - Lysichiton americanuswestern hemlock / western Labrador tea / slough sedge - skunk cabbage swampG1S1
Vaccinium uliginosum / Carex obnuptabog blueberry / slough sedge shrub swampG2S2
Vaccinium uliginosum / Deschampsia cespitosa - Carex obnuptabog blueberry / tufted hairgrass - slough sedge shrub swampG2S2

Forested Wetlands

Scientific NameCommon NameRank
Acer macrophyllum / Rubus spectabilisbigleaf maple / salmonberryG4S2
Alnus rubra / Athyrium filix-feminared alder / lady fernG1S1
Chamaecyparis lawsoniana / Lonicera hispidula / FestucaPort Orford cedar / hairy honeysuckle / fescueG3S2
Chamaecyparis nootkatensis / Oplopanax horridusAlaska cedar / devil's clubG3S2
Fraxinus latifolia - Populus balsamifera ssp. trichocarpa / Rubus spectabilisOregon ash - black cottonwood / salmonberryG3S2
Fraxinus latifolia / Juncus patensOregon ash / spreading rushG2S2
Picea sitchensis / Carex obnupta - Lysichitum americanumSitka spruce / slough sedge - skunk cabbageG3S1
Pinus contorta spp. contorta / Carex obnuptashorepine / slough sedgeG2S1
Populus tremuloides / Carex aquatilis var. aquatilisquaking aspen / aquatic sedgeG2S2
Populus tremuloides / Carex pellitaquaking aspen / woolly sedgeG2S2
Salix lucida ssp. lasiandra / Uritica dioica ssp. gracilisPacific willow / stinging nettleG2S2
Salix lutea / Carex utriculatarigid willow / beaked sedgeG4S2
Thuja plicata - Tsuga heterophylla / Lysichiton americanuswestern red cedar - western hemlock / skunk cabbageG3S1
Thuja plicata / Lysichiton americanuswestern red cedar / skunk cabbageG4S1
Thuja plicata / Oplopanax horriduswestern red cedar / devils clubG3S1
Tsuga heterophylla / Vaccinium alaskaense - Oplopanax horriduswestern hemlock / Alaska huckleberry - devil's clubG3S2

Freshwater Marshes

Scientific NameCommon NameRank
Glyceria grandisAmerican mannagrass marshG2S2
Ludwigia palustris - Polygonum hydropiperoideswater purslane - waterpepper marshG2S2
Sagittaria latifoliawapato marshG3S2
Torreyochloa pallida var. paucifloraweak alkaligrassG3S2

Freshwater Tidal

Scientific NameCommon NameRank
Caltha palustris - Lysichiton americanusyellow marshmarigold - skunk cabbageG3S2
Picea sitchensis / Cornus sericea / Lysichiton americanus ForestSitka spruce / red-osier dogwood / skunk cabbageG2S1
Typha angustifolia - Typha latifolianarrow leaved cattail - broad-leaved cattail marshG3S2


Scientific NameCommon NameRank
Allenrolfea occidentalisiodine bush playaG3S2
Alnus incana - Spiraea douglasiimountain alder - Douglas spiraeaG3S2
Artemisia cana / Eleocharis palustrissilver sagebrush / common spikerush playaGUS2
Artemisia cana / Poa fendlerianasilver sagebrush / Fendler bluegrass playaG4S2
Artemisia papposaOwyhee sagebrush playaG?S2
Leymus triticoides - Poa secunda ssp. juncifoliacreeping wildrye - alkali bluegrass playaG3S2
Sarcobatus vermiculatus / Leymus cinereusblack greasewood / basin wildrye playaG3S2

Riparian Wetlands

Scientific NameCommon NameRank
Acer circinatum - Alnus incanavine maple - mountain alderG2G3S2
Alnus incana - Betula occidentalismountain alder - western birchG2G3S1
Alnus incana - Symphoricarpos albusmountain alder - common snowberryG3S2
Alnus rhombifolia - Salix lucida ssp. caudatawhite alder - Pacific willowG4S2
Alnus rhombifolia / Betula occidentaliswhite alder / western birchG1S1
Alnus rhombifolia / Carex nudatawhite alder / torrent sedgeG1S1
Alnus rhombifolia / Cornus sericea ssp. sericeawhite alder / red-osier dogwoodGUS2
Alnus rhombifolia / Crataegus douglasiiwhite alder / black hawthornGUS1
Alnus rhombifolia / Philadelphus lewisiiwhite alder / mockorangeG1S1
Alnus rhombifolia / Prunus virginianawhite alder / chokecherryG2S1
Alnus rhombifolia / Rosa woodsiiwhite alder / Wood's roseG1S1
Alnus rubra / Physocarpus capitatusred alder / Pacific ninebarkG1S1
Betula occidentalis - Cornus sericeawestern birch - creek dogwoodG2G3S2
Betula occidentalis - Crataegus douglasiiwestern birch - black hawthornG1S1
Betula occidentalis - Philadelphus lewisiiwestern birch - mockorangeG2S2
Crataegus douglasii - Rosa woodsiiblack hawthorn - Wood's roseG2S1
Crataegus douglasii - Symphoricarpos albus - (Populus tremuloides)black hawthorn - common snowberry - (aspen)G1S1
Philadelphus lewisiimockorangeG2S2
Argentina egedii - Aster subspicatusPacific silverweed - Douglas aster salt marshG3S2
Pinus ponderosa / Crataegus douglasiiponderosa pine / black hawthornG1S1
Populus angustifolia / Alnus incanamountain cottonwood / mountain alderG3S1
Populus angustifolia / Cornus sericeamountain cottonwood / creek dogwoodG4S1
Populus balsamifera ssp. trichocarpa - Alnus rhombifoliablack cottonwood - white alderG1S1
Populus balsamifera ssp. trichocarpa - Alnus rubra / Rubus spectabilisblack cottonwood - red alder / salmonberryG2G3S2
Populus balsamifera ssp. trichocarpa / Alnus incanablack cottonwood / mountain alderG3S2
Populus balsamifera ssp. trichocarpa / Betula occidentalis - Salix sppblack cottonwood / western birch - willowG3S2
Populus balsamifera ssp. trichocarpa / Cornus sericea / Impatiens capensisblack cottonwood / creek dogwood / touch-me-notG1S1
Populus balsamifera ssp. trichocarpa / Crataegus douglasiiblack cottonwood / black hawthornG1S1
Populus balsamifera ssp. trichocarpa / Philadelphus lewisiiblack cottonwood / mockorangeG3S2
Populus balsamifera ssp. trichocarpa / Salix exiguablack cottonwood / coyote willowG2S2
Populus balsamifera ssp. trichocarpa / Salix lucida ssp. caudatablack cottonwood / Pacific willow riparianG2S2
Populus tremuloides / Alnus incana - Betula nana - Ribes spp.quaking aspen / mountain alder - birch - currantG1S1
Populus tremuloides / Salix scoulerianaquaking aspen / Scouler willowG4S2
Prunus virginianachokecherryG4S2
Ribes lacustre / Cinna latifolia - Glyceria striataprickly currant / drooping woodreed - fowl mannagrass riparianG2S2
Salix amygdaloides - Salix exiguapeachleaf willow - coyote willowG3S2, G1Q
Salix boothii - Salix eastwoodiae / Carex nigricansBooth willow - mountain willow riparian / black alpine sedgeG3S2
Salix boothii - Salix lemmonii / Aconitum columbianumBooth willow - Lemmon willow / Columbia monkshoodG3S2
Salix eriocephala - Ribes aureumrigid willow - golden currant riparianG3S2
Salix eriocephala - Salix exiguacoyote willow - rigid willowG3S2
Salix exigua - Salix lucida ssp. caudatacoyote willow - Pacific willowG2QS2
Salix exigua / Equisetum arvensecoyote willow / common horsetailG3S2
Salix geyeriana - Salix eriocephalaGeyer willow - rigid willowG3S1
Salix geyeriana - Salix lemmoniiGeyer willow - Lemmon willowG3S2
Salix lucida ssp. caudata / Rosa woodsiiPacific willow / Wood's roseG3S2
Salix lutea / Rosa woodsiirigid willow / golden currant - Wood's roseG3S2
Salix scoulerianaScouler willowG2S2
Spartina pectinataprairie cordgrass marshG3S1
Thuja plicata - (Alnus rubra) / Rubus spectabilis / Oxalis oreganawestern red cedar - (red alder) / salmonberry / Oregon oxalisG3S2
Thuja plicata / Athyrium filix-feminawestern red cedar / lady fernG3G4S2

Salt Marshes, Brackish Marshes

Scientific NameCommon NameRank
Argentina egedii - Aster subspicatusPacific silverweed - Douglas aster salt marshG3S2
Argentina egedii - Carex obnuptaPacific silverweed - slough sedge salt marshG4S2
Argentina egedii - Distichlis spicataPacific silverweed - salt grassG3S2
Argentina egedii - Juncus balticusPacific silverweed - Baltic rush salt marshG4S2
Carex lyngbyeiLyngby sedge freshwater marshG4S2
Carex lyngbyei - (Distichlis spicata - Triglochin maritimum)Lyngby sedge - (saltgrass - arrow grass) salt marshG4S2
Carex lyngbyei - Argentina egediiLyngby sedge - Pacific silverweed salt marshG4S2
Deschampsia cespitosa - (Carex lyngbyei - Distichlis spicata) salt marshtufted hairgrass - (Lyngby sedge - saltgrass) salt marshG3S2
Deschampsia cespitosa - Argentina egedii salt marshtufted hairgrass - Pacific silverweed salt marshG4S2
Deschampsia cespitosa - Juncus balticus salt marshtufted hairgrass - Baltic rush salt marshG4S2
Distichlis spicata - (Salicornia virginica)saltgrass - (glasswort) salt marshG4S2
Salicornia virginicaglasswort salt marshG4S2
Salicornia virginica - Distichlis spicata - Triglochin maritima - (Jaumea carnosa)glasswort - saltgrass - arrow grass - (jaumea) salt marshG3S2
Scirpus americanus (estuarine association)three-square bulrush salt marshG3S2
Scirpus maritimus (estuarine association)seacoast bulrush salt marshG3S2
Triglochin maritimum - (Salicornia virginiana)arrow grass - (glasswort) salt marshG4S2

Serpentine Fens

Scientific NameCommon NameRank
Carex californicaCalifornia sedge ultramafic fenG2S2
Chamaecyparis lawsoniana / Rhododendron occidentale / CarexPort Orford cedar / western azalea / sedge ultramafic riparianG2S2
Danthonia californica - Deschampsia cespitosa ultramafic fenCalifornia oatgrass - tufted hairgrass ultramafic fenG2S2
Danthonia californica - Deschampsia cespitosa ultramafic prairieCalifornia oatgrass - tufted hairgrass ultramafic prairieG2S2
Darlingtonia californica ultramafic fenDarlingtonia ultramafic fenG4?S2
Rhododendron occidentale / Camassia quamashwestern azalea / camas shrubG2S2

Snowbed Depressions

No rare plant associations currently listed by ORBIC

Spray Zones

No rare plant associations currently listed by ORBIC


No rare plant associations currently listed by ORBIC

Vernal Pools

Scientific NameCommon NameRank
Alopecurus saccatus - Plagiobothrys bracteatus vernal poolfoxtail - popcorn flower vernal poolGUS2
Deschampsia danthonoides - Danthonia unispicata vernal poolannual hairgrass - onespike oatgrass vernal poolG3S2
Deschampsia danthonoides - Plagiobothrys leptocladus vernal poolannual hairgrass - branched popcorn flower vernal poolG2S2
Deschampsia danthonoides vernal poolannual hairgrass vernal poolG2S2
Downingia elegans vernal poolcommon downingia vernal poolG2S1
Downingia yina - Navarretia leucocephala ssp. minima vernal poolCascade downingia - least navarretia vernal poolG2S2
Downingia yina - Plagiobothrys bracteatus vernal poolCascade downingia - bracted popcorn flower vernal poolG2S2
Eragrostis hypnoides - Gnaphalium palustre vernal poolcreeping lovegrass - lowland cudweed vernal poolG2S1
Eryngium petiolatum - Grindelia nana vernal poolcoyote-thistle - low gumweed vernal poolG2S1
Eryngium petiolatum - Lasthenia glaberrima vernal poolcoyote-thistle - smooth lasthenia vernal poolG2S1
Gratiola ebracteata - Plagiobothrys bracteatus vernal poolbractless hedge-hyssop - bracted popcorn flower vernal poolG2S2
Isoetes nuttallii - Plagiobothrys bracteatus vernal poolNuttall quillwort - bracted popcorn flower vernal poolG2S2
Lasthenia californica vernal poolgoldfields vernal poolG3S2
Myosurus minimus - Plagiobothrys bracteatus vernal poolmousetail - bracted popcorn flower vernal poolG2S2
Navarretia intertexta - Polygonum kelloggii vernal poolneedle-leaf navarretia - Kellogg knotweed vernal poolG2S2
Navarretia leucocephala - Plagiobothrys bracteatus vernal poolnavarretia - bracted popcorn flower vernal poolG2S2
Plagiobothrys bracteatus - Veronica peregrina vernal poolbracted popcorn-flower - purslane speedwell vernal poolG2S2
Plagiobothrys figuratus vernal poolfragrant popcorn-flower vernal poolG2S1
Plagiobothrys leptocladus - Veronica peregrina vernal poolslender-branched popcorn-flower - purslane speedwell vernal poolG2S2
Psilocarpus brevissimus vernal pooldwarf woolly-heads vernal poolG2S2
Triteleia hyacinthina - Deschampsia danthanoides vernal poolhyacinth brodiaea - annual hairgrass vernal poolG2S2

Wet Meadows

No rare plant associations currently listed by ORBIC

Wet Prairies

Scientific NameCommon NameRank
Carex apertaColumbia sedge marshG1S1
Carex densa - Deschampsia cespitosaDense sedge - tufted hairgrass prairieG2S2
Carex densa - Juncus patensdense sedge - spreading rush marshG2S2
Carex unilateralis - Hordeum brachyantherumone-sided sedge - meadow barley prairieG2S2
Deschampsia cespitosa - Danthonia californica valley prairietufted hairgrass - California oatgrass valley prairieG2S2
Eleocharis palustris - Carex unilateraliscreeping spikerush - one-sided sedge marshG2S2
Rosa nutkana / Deschampsia cespitosaNootka rose / tufted hairgrass brush prairieG2S2
Rosa nutkana / Oenanthe sarmentosaNootka rose / water parsley shrub swampG2S2
Vaccinium caespitosumDwarf blueberry brush prairieGUS1

Authored by John A. Christy, Wetlands Ecologist, Oregon Biodiversity Information Center and The Wetlands Conservancy (2009)