Persicaria hydropiperoides

(Michx.) Small

Mild Water-pepper

G5Secure Found in 2 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.147112
Element CodePDPGN0L170
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
IUCNLeast concern
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderPolygonales
FamilyPolygonaceae
GenusPersicaria
Synonyms
Polygonum hydropiperoidesMichx.
Other Common Names
Renouée faux-poivre-d'eau (FR) Swamp Smartweed (EN) swamp smartweed (EN)
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.
Taxonomic Comments
Treated as Persicaria hydropiperoides in Flora of North America Editorial Committee (2005).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-05-15
Change Date1985-05-11
Edition Date2025-05-15
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
Persicaria hydropiperoides is a perennial forb occurring as a native species in freshwater wetland and aquatic habitats of the Americas (North, Central, South) and Mexico. There are over 2,400 estimated occurrences of this taxon, which are potentially threatened by development, water diversion, alteration of hydrology, erosion, succession, recreational activities, invasive species, and other threats in some places. Little is known about threats or trends, but with a large range extent, high number of occurrences, abundant habitat, broad habitat preferences, and no obvious intrinsic vulnerabilities, Persicaria hydropiperoides is considered secure.
Range Extent Comments
Persicaria hydropiperoides occurs in the Americas, in North America, in southeastern and southwestern Canada, the United States, and Mexico, in Central America, and in South America (FNA 2005). In the United States and Canada, it occurs from southern Alaska and southwestern British Columbia south through California and some western states (except for Montana south through Utah and Colorado), east to Florida, and north to Ontario and Nova Scotia It also occurs elsewhere as an introduced taxon (POWO 2025). The native range extent was estimated 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). Range extent was estimated using herbarium specimens and photo-based observations documented between 1994 and 2025 (GBIF 2025, iNaturalist 2025, RARECAT 2025, SEINet 2025).
Occurrences Comments
By applying a 1 km separation distance to herbarium records and photo-based observations documented between 1994 and 2025, there are estimated to be over 2,400 occurrences rangewide (GBIF 2025, iNaturalist 2025, RARECAT 2025, SEINet 2025).
Threat Impact Comments
Although threats are not widely documented, Persicaria hydropiperoides is likely threatened by development, water diversion, alteration of hydrology, erosion, succession, recreational activities, invasive species, and other threats in some places, though there is insufficient data, including anecdotal accounts, to understand scope and severity of threats for this species.
Ecology & Habitat

Habitat

Persicaria hydropiperoides occurs in "wet banks and clearings, shallow water, marshes, moist prairies, [and] ditches" from 0-1500 m in elevation (FNA 2005). In the southeastern United States, it also occurs in swamp forests and streams (Weakley and the Southeastern Flora Team 2025).
Terrestrial Habitats
Grassland/herbaceous
Palustrine Habitats
HERBACEOUS WETLANDFORESTED WETLAND
Other Nations (2)
United StatesN5
ProvinceRankNative
OhioSNRYes
FloridaSNRYes
MichiganSNRYes
IowaS3Yes
GeorgiaSNRYes
ArkansasSNRYes
South CarolinaS5Yes
CaliforniaSNRYes
TexasSNRYes
New HampshireSNRYes
IdahoSNRYes
OregonSNRYes
MaineSNRYes
North DakotaS1Yes
KentuckyS5Yes
South DakotaSNRYes
PennsylvaniaS5Yes
TennesseeSNRYes
LouisianaSNRYes
VirginiaS5Yes
AlaskaS1Yes
ConnecticutSNRYes
WisconsinSNRYes
AlabamaSNRYes
West VirginiaS5Yes
New YorkSNRYes
MissouriSNRYes
VermontS3Yes
OklahomaSNRYes
District of ColumbiaSNRYes
WashingtonSNRYes
North CarolinaS5Yes
NebraskaS4Yes
MinnesotaSNRYes
MassachusettsSNRYes
ArizonaSNRYes
MississippiSNRYes
IndianaSNRYes
New JerseySNRYes
New MexicoSNRYes
MarylandS5Yes
DelawareS5Yes
NevadaS1Yes
KansasS4Yes
IllinoisS4Yes
Rhode IslandSNRYes
CanadaN5
ProvinceRankNative
British ColumbiaS4Yes
Nova ScotiaS5Yes
OntarioS5Yes
QuebecS3Yes
New BrunswickS4Yes
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undetermined

Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (2)
North Carolina (1)
AreaForestAcres
Catfish Lake NorthCroatan National Forest11,299
Texas (1)
AreaForestAcres
Little Lake CreekNational Forests in Texas596
References (9)
  1. Flora of North America Editorial Committee (FNA). 2005. Flora of North America north of Mexico. Vol. 5. Magnoliophyta: Caryophyllidae: Caryophyllales, Polygonales, and Plumbaginales. Oxford Univ. Press, New York. vii + 656 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. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  6. Plants of the World Online (POWO). 2025. Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Online. Available: https://powo.science.kew.org/ (accessed 2025).
  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).