Polemonium californicum (California Jacob's ladder)

Plate 1 figs. a–h

Polemonium californicum, photographed by Noland Martin — fig. a Noland Martin, CC BY 4.0 / 2021-07-13 / obs. 143204826

Polemonium californicum, photographed by John Brew — fig. b John Brew, CC BY 4.0 / obs. 150915853

Polemonium californicum, photographed by Steve Woodward — fig. c Steve Woodward, CC0 1.0 / obs. 141187446

Polemonium californicum, photographed by Paul McClellan — fig. e Paul McClellan, CC BY 4.0 / obs. 145999458

Polemonium californicum, photographed by Drew Meyer — fig. f Drew Meyer, CC0 1.0 / obs. 138002315

Polemonium californicum, photographed by David Anderson — fig. g David Anderson, CC BY 4.0 / obs. 132804511

Polemonium californicum, photographed by Cole Wolf — fig. h Cole Wolf, CC BY 4.0 / obs. 136152844

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 = 258 observations

133

Flowering observations of Polemonium californicum by month
Month	Observations
Jan	0
Feb	0
Mar	0
Apr	0
May	14
Jun	86
Jul	133
Aug	24
Sep	1
Oct	0
Nov	0
Dec	0

Peak flowering in Jul, from 258 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 12 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.

Polemonium californicum f. oreades (Gand.) Wherry
Polemonium californicum f. oregonense (Gand.) Wherry
Polemonium californicum f. paddoense (Gand.) Wherry
Polemonium californicum subsp. columbianum (Rydb.) Wherry
Polemonium calycinum Eastw.
Polemonium columbianum Rydb.
Polemonium oreades Gand.
Polemonium oregonense Gand.
Polemonium paddoense Gand.
Polemonium pulcherrimum subsp. tricolor (Eastw.) Brand
Polemonium pulcherrimum var. calycinum (Eastw.) Brand
Polemonium tricolor Eastw.

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.