Bidens cernuaL.

Nodding Beggarticks

WFO wfo-0000003695 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h

Bidens cernua, photographed by Johan Kjær Prehn
fig. a Johan Kjær Prehn, CC BY 4.0 / 2021-09-25 / obs. 160134127
Bidens cernua, photographed by Ryan Sorrells
fig. b Ryan Sorrells, CC BY 4.0 / obs. 159678609
Bidens cernua, photographed by Rob Foster
fig. c Rob Foster, CC BY 4.0 / obs. 159986847
Bidens cernua, photographed by Henry "Nick" Robertson
fig. d Henry "Nick" Robertson, CC BY-SA 4.0 / obs. 160379686
Bidens cernua, photographed by Mary Krieger
fig. e Mary Krieger, CC BY 4.0 / obs. 159421135
Bidens cernua, photographed by Erin Lalime
fig. f Erin Lalime, CC BY 4.0 / obs. 162820805
Bidens cernua, photographed by florawhite
fig. g florawhite, CC BY 4.0 / obs. 160887695
Bidens cernua, photographed by Силаева Татьяна Борисовна
fig. h Силаева Татьяна Борисовна, CC0 1.0 / obs. 159191939

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 = 1,958 observations

Peak flowering in Sep, from 1,958 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 36 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.

  • Bidens cernua f. cernua
  • Bidens cernua var. bidens Farw.
  • Bidens cernua var. coreopsis Pursh
  • Bidens cernua var. discoidea Wimm. & Grab.
  • Bidens cernua var. elatior Torr. ex Greene
  • Bidens cernua var. ligulata Bonnet
  • Bidens cernua var. monocephala Zersi ex Fiori
  • Bidens cernua var. nana Wimm. & Grab.
  • Bidens cernua var. nutans Osswald & Sagorski ex Sagorski
  • Bidens cernua var. radiata Roth
  • Bidens cernua var. rugosa Coss. & Germ.
  • Bidens ciliolata Greene
  • Bidens cusickii Greene
  • Bidens dentata Wiegand
  • Bidens elliptica (Wiegand) Gleason
  • Bidens elliptica var. elliptica
  • Bidens elliptica var. integra Wiegand
  • Bidens elliptica var. oligodonta Fernald & H.St.John
  • Bidens filamentosa Rydb.
  • Bidens gracilenta Greene
  • Bidens graveolens Komarov
  • Bidens kelloggii Greene
  • Bidens leptomeria Greene
  • Bidens leptopoda Greene

and 12 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.

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.