Trillium undulatumWilld.

painted trillium

WFO wfo-0000749535 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h

Trillium undulatum, photographed by Bruce Cook
fig. a Bruce Cook, CC0 1.0 / 2022-06-11 / obs. 205165230
Trillium undulatum, photographed by Steven Lamonde
fig. b Steven Lamonde, CC BY 4.0 / obs. 205766186
Trillium undulatum, photographed by Mary E. Macaulay, P.Eng.
fig. c Mary E. Macaulay, P.Eng., CC BY 4.0 / obs. 204512313
Trillium undulatum, photographed by Steven Lamonde
fig. d Steven Lamonde, CC BY 4.0 / obs. 205766486
Trillium undulatum, photographed by Alexis Godin
fig. e Alexis Godin, CC BY 4.0 / obs. 202452299
Trillium undulatum, photographed by Clay Gibbons
fig. f Clay Gibbons, CC BY 4.0 / obs. 201763366
Trillium undulatum, photographed by Steven Lamonde
fig. g Steven Lamonde, CC BY 4.0 / obs. 205763648
Trillium undulatum, photographed by Jim Bennett
fig. h Jim Bennett, CC0 1.0 / obs. 201746862

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.

Flowering n = 7,788 observations

Peak flowering in May, from 7,788 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 10 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.

  • Trillidium undulatum (Willd.) Floden & E.E.Schill.
  • Trillium cleavelandicum Alph.Wood
  • Trillium erythrocarpum Michx.
  • Trillium erythrocarpum var. cleavelandicum Alph.Wood
  • Trillium pictum Pursh
  • Trillium undulatum f. cleavelandicum (Alph.Wood) Fernald
  • Trillium undulatum f. enotatum T.S.Patrick
  • Trillium undulatum f. polymerum Vict. ex Louis-Marie
  • Trillium undulatum f. striatum Louis-Marie
  • Trillium undulatum f. undulatum

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.