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Home/Species/ Red-root Amaranth

Amaranthus retroflexus

L.

Red-root Amaranth

G5Secure Found in 15 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.138217
Element CodePDAMA04100
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderCaryophyllales
FamilyAmaranthaceae
GenusAmaranthus
Other Common Names
Amarante à racine rouge (FR) redroot amaranth (EN) Redroot Pigweed (EN) Rough Pigweed (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.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2024-08-08
Change Date2015-06-01
Edition Date2024-08-08
Edition AuthorsN. Ventrella (2024)
Threat ImpactUnknown
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Number of Occurrences> 300
Rank Reasons
Amaranthus retroflexus is an annual herb occurring in a variety of habitat types, including riverbanks, lakeshores, and stream edges, disturbed areas, fields, railway and road corridors, and waste areas. It is a successful introduced and invasive species to most inhabited continents worldwide, though its native range is presumably central and eastern North America. With a large range extent, more than 4,000 occurrences, abundant habitat, broad habitat preferences, and no obvious intrinsic vulnerabilities, this species is considered secure.
Range Extent Comments
Amaranthus retroflexus is an extremely widespread species that is presumably native to central and eastern North America, but which has been introduced and naturalized worldwide (FNA 2003, Weakley and the Southeastern Flora Team 2024). The native range of this species is now nearly impossible to determine (Weakley and the Southeastern Flora Team 2024). Range extent was estimated to be over 100 million square kilometers using herbarium specimens and photo-based observations documented between 2022 and 2024 (GBIF 2024, iNaturalist 2024, SEINet 2024).
Occurrences Comments
By applying a 1 km separation distance to herbarium records and photo-based observations documented between 2022 and 2024, there are estimated to be over 4,000 occurrences rangewide (GBIF 2024, iNaturalist 2024, SEINet 2024).
Threat Impact Comments
Although threats are not widely documented, Amaranthus retroflexus is potentially threatened by development, road maintenance, invasive species, and other threats in some places. However, their overall impact is likely negligible given the species' broad range, large number of occurrences, tolerance of disturbance, and affinity for typically abundant habitats, as well as no obvious intrinsic vulnerabilities.
Ecology & Habitat

Habitat

In North America, Amaranthus retroflexus occurs on "banks of rivers, lakes, and streams, disturbed habitats, agricultural fields, railroads, roadsides, [and] waste areas" (FNA 2003).
Terrestrial Habitats
Forest EdgeOld field
Palustrine Habitats
FORESTED WETLANDRiparian
Other Nations (2)
CanadaNNA
ProvinceRankNative
OntarioSNANo
Island of NewfoundlandSNANo
SaskatchewanSNANo
ManitobaSNANo
QuebecSNANo
New BrunswickSNANo
British ColumbiaSNANo
Nova ScotiaSNANo
Prince Edward IslandSNANo
AlbertaSNANo
United StatesN5
ProvinceRankNative
WisconsinSNANo
North DakotaSNANo
ArkansasSNANo
ConnecticutSNANo
Navajo NationSNRYes
ColoradoSNANo
North CarolinaSNANo
OregonSNANo
AlaskaSNANo
ArizonaSNANo
New JerseySNANo
UtahSNANo
PennsylvaniaSNANo
MarylandSNANo
VermontS5Yes
GeorgiaSNANo
South DakotaSNANo
South CarolinaSNRYes
DelawareSNANo
OhioSNANo
MichiganSNANo
IndianaSNANo
WyomingS3Yes
VirginiaSNANo
WashingtonSNANo
IowaSNANo
MissouriSNANo
New MexicoSNANo
TexasSNANo
IllinoisSNANo
MinnesotaSNANo
AlabamaSNANo
New HampshireSNANo
NebraskaSNANo
LouisianaSNANo
West VirginiaSNANo
Rhode IslandSNANo
OklahomaSNANo
KansasS5Yes
IdahoSNANo
MississippiSNANo
New YorkSNANo
TennesseeSNANo
MaineSNANo
District of ColumbiaSNANo
CaliforniaSNANo
MontanaSNRYes
KentuckySNANo
NevadaSNANo
MassachusettsSNRYes
FloridaSNANo
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undetermined———

—

Plant Characteristics
DurationANNUAL
Economic Value (Genus)Yes
Roadless Areas (15)
Montana (3)
AreaForestAcres
Patricks Knob - North CutoffLolo National Forest16,970
South Siegel - South CutoffLolo National Forest13,474
Stony MountainBitterroot National Forest44,057
New Mexico (8)
AreaForestAcres
Alamo CanyonSanta Fe National Forest8,639
Bull CanyonCarson National Forest11,512
Chama WS RiverSanta Fe National Forest4,168
Columbine - Hondo Wilderness Study AreaCarson National Forest43,739
GallinasSanta Fe National Forest13,208
Latir PeakCarson National Forest3,573
Nichols ReservoirSanta Fe National Forest1,518
RendijaSanta Fe National Forest2,176
Utah (4)
AreaForestAcres
418012Uinta National Forest25,758
418025Uinta National Forest32,698
Lewis PeakWasatch-Cache National Forest11,616
South FrancisWasatch-Cache National Forest3,374
References (6)
  1. Flora of North America Editorial Committee (FNA). 2003b. Flora of North America north of Mexico. Vol. 4, Magnoliophyta: Caryophyllidae, part 1. Oxford University Press, New York. xxiv + 559 pp.
  2. Global Biodiversity Information Facility (GBIF). 2024. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2024).
  3. iNaturalist. 2024. Online. Available: https://www.inaturalist.org (accessed 2024).
  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. Southwest Environmental Information Network (SEINet). 2024. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2024).
  6. Weakley, A.S., and Southeastern Flora Team. 2024. Flora of the southeastern United States. Edition of March 4, 2024. University of North Carolina Herbarium (NCU), North Carolina Botanical Garden, University of North Carolina, Chapel Hill. 2203 pp.