Trillium ovatum (Pacific trillium)

Plate 1 figs. a–e

Trillium ovatum, photographed by Casey H. Richart — fig. a Casey H. Richart, CC BY 4.0 / 2022-05-30 / obs. 202614849

Trillium ovatum, photographed by David Anderson — fig. b David Anderson, CC BY 4.0 / obs. 201141681

Trillium ovatum, photographed by humon — fig. c humon, CC BY 4.0 / obs. 201766229

Trillium ovatum, photographed by sprcrkwild — fig. d sprcrkwild, CC BY 4.0 / obs. 201005350

Trillium ovatum, photographed by Tuoichen — fig. e Tuoichen, CC BY 4.0 / obs. 200654849

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 = 15,075 observations

1099

3813

6421

2756

746

154

Flowering observations of Trillium ovatum by month
Month	Observations
Jan	66
Feb	1099
Mar	3813
Apr	6421
May	2756
Jun	746
Jul	154
Aug	4
Sep	6
Oct	4
Nov	3
Dec	3

Peak flowering in Apr, from 15,075 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 7 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.

Trillium californicum Kellogg
Trillium obovatum Hook.
Trillium ovatum f. maculosum Case & R.B.Case
Trillium ovatum subsp. oettingeri Munz & Thorne
Trillium ovatum subsp. ovatum
Trillium ovatum var. stenosepalum R.R.Gates
Trillium venosum R.R.Gates

Sourcesevery claim on this page

World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
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.