Grindelia squarrosa(Pursh) Dunal

Curlycup Gumweed

WFO wfo-0000126982 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h

Grindelia squarrosa, photographed by Kalvin Chan
fig. a Kalvin Chan, CC BY 4.0 / 2021-10-21 / obs. 164828499
Grindelia squarrosa, photographed by Anna Petrosyan
fig. b Anna Petrosyan, CC BY 4.0 / obs. 172513696
Grindelia squarrosa, photographed by Jay Pruett
fig. c Jay Pruett, CC BY 4.0 / obs. 166740379
Grindelia squarrosa, photographed by Valerii Darmostuk
fig. d Valerii Darmostuk, CC BY 4.0 / obs. 168344347
Grindelia squarrosa, photographed by Dominic Gentilcore
fig. e Dominic Gentilcore, CC BY 4.0 / obs. 161574647
Grindelia squarrosa, photographed by tzeducation
fig. f tzeducation, CC BY 4.0 / obs. 160265422
Grindelia squarrosa, photographed by Nart Barileva
fig. g Nart Barileva, CC0 1.0 / obs. 166984001
Grindelia squarrosa, photographed by Valerii Darmostuk
fig. h Valerii Darmostuk, CC BY 4.0 / obs. 168064553

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 = 2,115 observations

Peak flowering in Aug, from 2,115 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 19 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.

  • Aurelia amplexicaulis Cass.
  • Aurelia squarrosa (Pursh) Cass. ex Steud.
  • Donia squarrosa Pursh
  • Grindelia aphanactis Rydb.
  • Grindelia arguta A.Gray
  • Grindelia nuda Alph.Wood
  • Grindelia nuda var. aphanactis (Rydb.) G.L.Nesom
  • Grindelia pinnatifida Wooton & Standl.
  • Grindelia serrulata Rydb.
  • Grindelia squarrosa f. angustior Steyerm.
  • Grindelia squarrosa f. depressa Steyerm.
  • Grindelia squarrosa f. pseudopinnatifida (D.Löve & J.-P.Bernard) Adr.Bartoli & Tortosa
  • Grindelia squarrosa f. squarrosa
  • Grindelia squarrosa var. eligulata (Steyerm.) Adr.Bartoli & Tortosa
  • Grindelia squarrosa var. grandiflora (Hook.) A.Gray
  • Grindelia squarrosa var. nuda (Alph.Wood) A.Gray
  • Grindelia squarrosa var. serrulata Steyerm.
  • Grindelia squarrosa var. squarrosa
  • Hysterionica squarrosa Baill.

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.