Ambrosia artemisiifoliaL.

common ragweed

WFO wfo-0000063493 Accepted WFO 2026-06 8 photographs CC0 / CC BY In the accuracy benchmark

Plate 1 figs. a–h

Ambrosia artemisiifolia, photographed by Юрий Данилевский (Yuriy Danilevsky)
fig. a Юрий Данилевский (Yuriy Danilevsky), CC BY 4.0 / 2022-06-12 / obs. 205758420
Ambrosia artemisiifolia, photographed by Randy A Nonenmacher
fig. b Randy A Nonenmacher, CC BY 4.0 / obs. 205043117
Ambrosia artemisiifolia, photographed by Violet T.
fig. c Violet T., CC BY 4.0 / obs. 202269953
Ambrosia artemisiifolia, photographed by Joseph Aubert
fig. d Joseph Aubert, CC BY 4.0 / obs. 205357336
Ambrosia artemisiifolia, photographed by Dilrukshan Priyantha Wijesinghe
fig. e Dilrukshan Priyantha Wijesinghe, CC BY 4.0 / obs. 203653218
Ambrosia artemisiifolia, photographed by Liubov Ilminska
fig. f Liubov Ilminska, CC0 1.0 / obs. 201694282
Ambrosia artemisiifolia, photographed by Dilrukshan Priyantha Wijesinghe
fig. g Dilrukshan Priyantha Wijesinghe, CC BY 4.0 / obs. 204161934
Ambrosia artemisiifolia, photographed by Bruce Slater
fig. h Bruce Slater, CC BY 4.0 / obs. 201128097

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.

Confused withby our own model

These are not lookalikes we guessed at. Each one is a species our identification model genuinely mistook for this plant, and how many times. The error rate is published.

Flowering n = 1,151 observations

Peak flowering in Aug, from 1,151 community-annotated observations worldwide. This is a global aggregate, not a forecast for your garden: the same species flowers on different dates in different hemispheres, and citizen-science records cluster near cities, at weekends, and in spring. Where a species has fewer than 30 annotated records we do not draw this chart at all.

Also published as 18 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.

  • Ambrosia artemisiifolia f. artemisiifolia
  • Ambrosia artemisiifolia subsp. artemisiifolia
  • Ambrosia artemisiifolia subsp. diversifolia Piper
  • Ambrosia artemisiifolia var. artemisiifolia
  • Ambrosia artemisiifolia var. diversifolia Piper
  • Ambrosia artemisiifolia var. elatior (L.) Descourt.
  • Ambrosia artemisiifolia var. jamaicensis Griseb.
  • Ambrosia chilensis Hook. & Arn.
  • Ambrosia elata Salisb.
  • Ambrosia elatior L.
  • Ambrosia elatior var. elatior
  • Ambrosia glandulosa Scheele
  • Ambrosia monophylla (Walter) Rydb.
  • Ambrosia paniculata Michx.
  • Ambrosia paniculata f. paniculata
  • Ambrosia paniculata var. paniculata
  • Ambrosia peruviana Cabrera
  • Iva monophylla Walter

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.

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