Amaranthus cannabinus(L.) Sauer

tidalmarsh amaranth

WFO wfo-0000530115 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Amaranthus cannabinus, photographed by Susan Christman Williams
fig. a Susan Christman Williams, CC0 1.0 / 2021-08-14 / obs. 150665468
Amaranthus cannabinus, photographed by Susan Christman Williams
fig. b Susan Christman Williams, CC0 1.0 / obs. 150665650
Amaranthus cannabinus, photographed by Tom Field
fig. c Tom Field, CC BY 4.0 / obs. 94844134
Amaranthus cannabinus, photographed by Zihao Wang
fig. d Zihao Wang, CC BY 4.0 / obs. 22710379
Amaranthus cannabinus, photographed by Susan Christman Williams
fig. e Susan Christman Williams, CC0 1.0 / obs. 149148911
Amaranthus cannabinus, photographed by Tom Field
fig. f Tom Field, CC BY 4.0 / obs. 148875651
Amaranthus cannabinus, photographed by Tom Field
fig. g Tom Field, CC BY 4.0 / obs. 98546224
Amaranthus cannabinus, photographed by Sandy Wolkenberg
fig. h Sandy Wolkenberg, CC BY 4.0 / obs. 92876491

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.

Where it actually grows measured, from 295 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -6.2 °C -1.1 °C 6.6 °C
Warmest month, mean daily high 24.8 °C 28.7 °C 31.7 °C
Annual rainfall 1,077 mm 1,181 mm 1,303 mm
Rainfall in the driest quarter 221 mm 255 mm 291 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 295 research-grade observations of Amaranthus cannabinus 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 Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one.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 11 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 cannabina L.
  • Acnida cannabina var. concatenata Moq.
  • Acnida cannabina var. cuspidata (Bertero ex Spreng.) Moq.
  • Acnida cannabina var. lanceolata Moq.
  • Acnida cannabina var. salicifolia Moq.
  • Acnida elliotii Raf.
  • Acnida obtusifolia Raf.
  • Acnida rhyssocarpa Steud.
  • Acnida ruscocarpa Willd.
  • Acnida salicifolia Raf.
  • Amaranthus macrocaulos Poir.

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.

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. It has no native range either: Kew's checklist does not cover this taxon.