Balsamorhiza hookeri (Hooker's balsamroot)

Plate 1 figs. a–h · 8 separate observations

Balsamorhiza hookeri, photographed by Tim Messick — fig. a Tim Messick, CC BY 4.0 / 2022-05-22 / obs. 203312858

Balsamorhiza hookeri, photographed by Trevor Van Loon — fig. b Trevor Van Loon, CC BY 4.0 / obs. 196125680

Balsamorhiza hookeri, photographed by James H. Thomas — fig. c James H. Thomas, CC BY 4.0 / obs. 194564612

Balsamorhiza hookeri, photographed by Cindy Bell — fig. e Cindy Bell, CC BY 4.0 / obs. 192564544

Balsamorhiza hookeri, photographed by Tuoichen — fig. g Tuoichen, CC BY 4.0 / obs. 193310090

Balsamorhiza hookeri, photographed by Grant Chovil — fig. h Grant Chovil, CC BY 4.0 / obs. 189567813

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.

Native range 6 botanical countries

Native distribution of Balsamorhiza hookeri, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows.

Region	TDWG code	Continent
California	CAL	NORTHERN AMERICA
Idaho	IDA
Nevada	NEV
Oregon	ORE
Utah	UTA
Washington	WAS

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Flowering 220 in flower of 252 examined

76%

92%

94%

36%

Proportion of examined Balsamorhiza hookeri in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	0	0	too few examined
Feb	0	0	too few examined
Mar	26	34	76%	60% to 88%
Apr	92	100	92%	85% to 96%
May	95	101	94%	88% to 97%
Jun	5	14	36%	16% to 61%
Jul	1	1	too few examined
Aug	0	1	too few examined
Sep	1	1	too few examined
Oct	0	0	too few examined
Nov	0	0	too few examined
Dec	0	0	too few examined

Peak flowering in May. Each bar is the share of Balsamorhiza hookeri observations in which someone actually recorded the reproductive state and found the plant in flower, not the raw number of flowering records. That distinction matters: people observe plants far more in spring than in winter, so a bare count of flowering records partly measures when people go outside. Dividing by the number examined removes that. 220 of 252 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 8 months have fewer than 5 examined observations, so no proportion is drawn for them. This is still a global aggregate and not a forecast for your garden: the same species flowers on different dates in different hemispheres. Where a species has fewer than 30 flowering records we do not draw this chart at all. Computed from 10.15468/dl.cgje2x.

Where it actually grows measured, from 1,408 observations

Condition	5th percentile	Median	95th percentile
Coldest month, mean daily low	-10.2 °C	-6.4 °C	-3.6 °C
Warmest month, mean daily high	26.1 °C	29.8 °C	32.4 °C
Annual rainfall	183 mm	307 mm	713 mm
Rainfall in the driest quarter	19 mm	29 mm	72 mm

It is found where winters bring hard frost. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 1,408 research-grade observations of Balsamorhiza hookeri that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one. Climate from CHELSA V2.1 (Karger et al. 2017); occurrences from 10.15468/dl.cgje2x.

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.

Balsamorhiza balsamorhiza (Hook.) A.Heller
Balsamorhiza hirsuta Nutt.
Balsamorhiza hirsuta var. hirsuta
Balsamorhiza hirsuta var. lagocephala W.M.Sharp
Balsamorhiza hirsuta var. neglecta W.M.Sharp
Balsamorhiza hookeri var. hookeri
Balsamorhiza hookeri var. platylepis (W.M.Sharp) Cronquist
Balsamorhiza macrophylla var. idahoensis W.M.Sharp
Balsamorhiza platylepis W.M.Sharp
Heliopsis balsamorhiza Hook.

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.
Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.