Amaranthus tuberculatus(Moq.) J.D.Sauer

roughfruit amaranth

WFO wfo-0000530532 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Amaranthus tuberculatus, photographed by Jay Pruett
fig. a Jay Pruett, CC BY 4.0 / 2021-10-12 / obs. 163325144

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

The specimen a real sheet, in a real collection

Herbarium
The New York Botanical Garden
Accession
3365011
Filed as
Amaranthus tuberculatus (Moq.) J.D.Sauer
Det. by
K. E. Waselkov 2022-08-01
Collected
not recorded
Origin
not recorded
The sheet
View the digitised specimen (CC BY 4.0)

A real pressed plant, in a real collection, under the accession number above. Not an illustration of one. The holding institution does not serve this sheet’s image to third parties, so there is no photograph here. The record is real and the link goes to it. Where we hold no openly licensed sheet for a species this section is simply absent, and where a sheet never recorded who determined it, that field stays empty rather than being filled in. Roughly half of all herbarium sheets never recorded a determiner, which is ordinary.

Native range 25 botanical countries

Regions where Amaranthus tuberculatus is native: Alabama, Arkansas, Connecticut, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New York, North Dakota, Ohio, Oklahoma, South Dakota, Tennessee, Texas, Vermont, Wisconsin AlabamaArkansasConnecticutIllinoisIndianaIowaKansasKentuckyLouisianaMaineMassachusettsMichiganMinnesotaMississippiMissouriNebraskaNew YorkNorth DakotaOhioOklahomaSouth DakotaTennesseeTexasVermontWisconsin
Native distribution of Amaranthus tuberculatus, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows.
RegionTDWG codeContinent
Alabama ALA NORTHERN AMERICA
Arkansas ARK
Connecticut CNT
Illinois ILL
Indiana INI
Iowa IOW
Kansas KAN
Kentucky KTY
Louisiana LOU
Maine MAI
Massachusetts MAS
Michigan MIC
Minnesota MIN
Mississippi MSI
Missouri MSO
Nebraska NEB
New York NWY
North Dakota NDA
Ohio OHI
Oklahoma OKL
South Dakota SDA
Tennessee TEN
Texas TEX
Vermont VER
Wisconsin WIS

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Where it actually grows measured, from 160 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -13.5 °C -6.8 °C 6.0 °C
Warmest month, mean daily high 25.5 °C 28.4 °C 34.1 °C
Annual rainfall 723 mm 972 mm 1,364 mm
Rainfall in the driest quarter 52 mm 153 mm 258 mm

It is found where winters bring hard frost. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 160 research-grade observations of Amaranthus tuberculatus that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one.

Also published as 25 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Acnida altissima (Riddell) Moq.
  • Acnida altissima var. prostrata (Uline & W.L.Bray) Fernald
  • Acnida altissima var. subnuda (S.Watson ex A.Gray) Fernald
  • Acnida cannabina var. prostrata (Uline & W.L.Bray) Fernald
  • Acnida cannabina var. subnuda (S.Watson) Fernald
  • Acnida concatenata (Moq.) Small
  • Acnida subnuda (S.Watson) Standl.
  • Acnida tamariscina var. concatenata Uline & W.L.Bray
  • Acnida tamariscina var. prostrata Uline & W.L.Bray
  • Acnida tamariscina var. subnuda (S.Watson) J.M.Coult.
  • Acnida tamariscina var. tuberculata (Moq.) Uline & W.L.Bray
  • Acnida tuberculata Moq.
  • Acnida tuberculata var. prostrata (Uline & W.L.Bray) B.L.Rob.
  • Acnida tuberculata var. prostrata (Uline & W.L.Bray) Lunell
  • Acnida tuberculata var. subnuda S.Watson
  • Amaranthus altissimus Riddell
  • Amaranthus ambigens Standl.
  • Amaranthus cannabinus var. concatenatus Moq.
  • Amaranthus miamiensis Riddell
  • Amaranthus rudis J.D.Sauer
  • Amaranthus tuberculatus var. prostratus (Uline & W.L.Bray) Mohlenbr.
  • Amaranthus tuberculatus var. rudis (J.D.Sauer) Costea & Tardif
  • Amaranthus tuberculatus var. subnudus (S.Watson) Mohlenbr.
  • Montelia tamariscina (Nutt.) A.Gray

and 1 more.

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
  4. Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.