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Cardamine diphylla

(Michx.) Wood

Twoleaf Toothwort

G5Secure Found in 46 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.154861
Element CodePDBRA0K170
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderCapparales
FamilyBrassicaceae
GenusCardamine
Synonyms
Dentaria diphyllaMichx.Dentaria incisaSmall
Other Common Names
crinkleroot (EN) Crinkleroot (EN) Dentaire à deux feuilles (FR)
Concept Reference
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-07-15
Change Date1984-04-24
Edition Date2025-07-15
Edition AuthorsN. Ventrella (2025)
Threat ImpactUnknown
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Number of Occurrences> 300
Rank Reasons
Cardamine diphylla is a perennial forb occurring in woodlands, forests, cliffs, ledges, meadows, and alluvial banks of eastern North America, from Ontario and Nova Scotia, Canada, south to Georgia, South Carolina, and Alabama in the United States. There are several thousand estimated occurrences rangewide, which are threatened by invasive species, recreation, succession, development, logging, rights-of-way construction and maintenance, and likely other threats in some places. Little is known about trends, but with a large range extent, abundant habitat, and broad habitat preferences, Cardamine diphylla is considered secure.
Range Extent Comments
Cardamine diphylla occurs in eastern North America, from Ontario and Nova Scotia, Canada south to Georgia, South Carolina, and Alabama in the United States (FNA 2010, Weakley and the Southeastern Flora Team 2025). Range extent was estimated to be over 2.9 million square kilometers using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1994 and 2025 (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Occurrences Comments
By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025, it is estimated that there are several thousand occurrences rangewide (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Threat Impact Comments
Threats to Cardamine diphylla are not well documented but include invasive species, recreation, succession, development, logging, rights-of-way construction and maintenance, and likely other threats in some places (NatureServe 2025). However, these threats are considered negligible given the broad range and large number of occurrences of the species.
Ecology & Habitat

Habitat

Cardamine diphylla occurs in "wooded bottoms and ravines, cliffs, bluffs, ledges, shaded slopes, meadows, moist fields, alluvial banks, [and] rich woods" from 50-1300 m in elevation (FNA 2010).

Reproduction

Cardamine diphylla produces flowers from April through June (FNA 2010).
Terrestrial Habitats
Forest/WoodlandGrassland/herbaceousCliff
Palustrine Habitats
FORESTED WETLANDRiparian
Other Nations (2)
United StatesN5
ProvinceRankNative
DelawareSNANo
MissouriSNRYes
TennesseeS3Yes
PennsylvaniaS5Yes
IllinoisSNRYes
MarylandSNRYes
ArkansasSNRYes
VirginiaS4Yes
New JerseyS2Yes
AlabamaSNRYes
VermontS4Yes
New YorkS5Yes
New HampshireSNRYes
South CarolinaS2Yes
ConnecticutSNRYes
West VirginiaS5Yes
OhioSNRYes
MaineSNRYes
WisconsinSNRYes
IndianaS3Yes
MinnesotaSNRYes
MississippiS1Yes
KentuckyS5Yes
MassachusettsSNRYes
GeorgiaSNRYes
MichiganSNRYes
North CarolinaS5Yes
CanadaN5
ProvinceRankNative
Prince Edward IslandS1Yes
Nova ScotiaS4Yes
QuebecS4Yes
OntarioS5Yes
New BrunswickS4Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentUnknownUnknownUnknown
4 - Transportation & service corridorsUnknownUnknownUnknown
5 - Biological resource useUnknownUnknownUnknown
5.3 - Logging & wood harvestingUnknownUnknownUnknown
6 - Human intrusions & disturbanceUnknownUnknownUnknown
6.1 - Recreational activitiesUnknownUnknownUnknown
7 - Natural system modificationsUnknownUnknownUnknown
7.1 - Fire & fire suppressionUnknownUnknownUnknown
7.1.2 - Suppression in fire frequency/intensityUnknownUnknownUnknown
8 - Invasive & other problematic species, genes & diseasesUnknownUnknownUnknown
8.1 - Invasive non-native/alien species/diseasesUnknownUnknownUnknown
8.1.1 - Unspecified speciesUnknownUnknownUnknown

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (46)
Georgia (4)
AreaForestAcres
Joe GapChattahoochee National Forest5,321
Patterson GapChattahoochee National Forest1,186
Pink KnobChattahoochee National Forest12,127
Rocky MountainChattahoochee National Forest4,269
Kentucky (1)
AreaForestAcres
WolfpenDaniel Boone National Forest2,835
North Carolina (11)
AreaForestAcres
Bald MountainPisgah National Forest11,085
BearwallowPisgah National Forest4,113
Cheoah BaldNantahala National Forest7,795
Craggy MountainPisgah National Forest2,657
Jarrett CreekPisgah National Forest7,485
Linville Gorge AdditionPisgah National Forest2,809
Little Indian (addition)Nantahala National Forest640
Mackey MountainPisgah National Forest5,934
Sam Knob (addition)Pisgah National Forest2,576
Tusquitee BaldNantahala National Forest13,670
Wesser BaldNantahala National Forest4,061
Pennsylvania (3)
AreaForestAcres
Allegheny FrontAllegheny National Forest7,430
Minister ValleyAllegheny National Forest1,417
Tracy RidgeAllegheny National Forest9,034
Tennessee (5)
AreaForestAcres
Bald MountainCherokee National Forest11,743
Brushy RidgeCherokee National Forest7,469
Devil's BackboneCherokee National Forest4,287
Joyce Kilmer Slickrock Add.Cherokee National Forest1,396
Stone MountainCherokee National Forest5,367
Vermont (4)
AreaForestAcres
Bread LoafGreen Mountain and Finger Lakes National Forests1,768
Devil's Den 09083Green Mountain and Finger Lakes National Forests9,169
Griffith Lake 09084Green Mountain and Finger Lakes National Forests1,833
Wilder Mountain 09082Green Mountain and Finger Lakes National Forests8,759
Virginia (4)
AreaForestAcres
Bear CreekJefferson National Forest18,274
Gum RunGeorge Washington National Forest12,620
Laurel ForkGeorge Washington National Forest9,967
Ramseys Draft AdditionGeorge Washington National Forest12,781
West Virginia (13)
AreaForestAcres
Canaan LoopMonongahela National Forest7,867
Cranberry AdditionMonongahela National Forest11,123
Cranberry Glades Botanical AreaMonongahela National Forest785
Dolly Sods Roaring PlainMonongahela National Forest13,392
Dry ForkMonongahela National Forest657
East Fork Of GreenbrierMonongahela National Forest7,167
Falls Of Hills CreekMonongahela National Forest6,925
Glady ForkMonongahela National Forest3,239
Laurel ForkMonongahela National Forest1,172
Mcgowan MountainMonongahela National Forest10,504
Middle MountainMonongahela National Forest19,020
Seneca CreekMonongahela National Forest22,287
Tea Creek MountainMonongahela National Forest8,295
Wisconsin (1)
AreaForestAcres
09182 - Pentoga RoadChequamegon-Nicolet National Forest5,008
References (9)
  1. Flora of North America Editorial Committee (FNA). 2010. Flora of North America north of Mexico. Vol. 7. Magnoliophyta: Salicaceae to Brassicaceae. Oxford University Press, New York. xxii + 797 pp.
  2. Global Biodiversity Information Facility (GBIF). 2025. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2025).
  3. iNaturalist. 2025. Online. Available: https://www.inaturalist.org (accessed 2025).
  4. Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
  5. Native Plant Trust. 2025. Go Botany website. Online. Available: https://gobotany.nativeplanttrust.org (accessed 2025).
  6. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  7. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  8. Southwest Environmental Information Network (SEINet). 2025. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2025).
  9. Weakley, A.S., and Southeastern Flora Team. 2025. Flora of the southeastern United States Web App. Edition of February 18, 2025. University of North Carolina Herbarium (NCU), North Carolina Botanical Garden, University of North Carolina, Chapel Hill. Online. Available: https://fsus.ncbg.unc.edu (accessed 2025).