Thamnosma montana (turpentinebroom)

Plate 1 figs. a–h · 8 separate observations

Thamnosma montana, photographed by Kyle Nessen — fig. a Kyle Nessen, CC0 1.0 / 2022-04-22 / obs. 190784361

Thamnosma montana, photographed by CK2AZ — fig. b CK2AZ, CC BY 4.0 / obs. 189349448

Thamnosma montana, photographed by Craig Martin — fig. c Craig Martin, CC0 1.0 / obs. 183276708

Thamnosma montana, photographed by Kenzie Anderson-Bell — fig. d Kenzie Anderson-Bell, CC BY 4.0 / obs. 182399726

Thamnosma montana, photographed by Bobby McCabe — fig. e Bobby McCabe, CC BY 4.0 / obs. 180630449

Thamnosma montana, photographed by Arvel Hernandez — fig. f Arvel Hernandez, CC BY-SA 4.0 / obs. 180360135

Thamnosma montana, photographed by Henrik Kibak — fig. g Henrik Kibak, CC BY 4.0 / obs. 182407452

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 5 botanical countries

Native distribution of Thamnosma montana, 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
Arizona	ARI	NORTHERN AMERICA
California	CAL
Mexico Northwest	MXN
Nevada	NEV
Utah	UTA

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 531 in flower of 857 examined

75%

93%

88%

55%

13%

15%

50%

Proportion of examined Thamnosma montana in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	46	61	75%	63% to 84%
Feb	155	167	93%	88% to 96%
Mar	200	227	88%	83% to 92%
Apr	92	168	55%	47% to 62%
May	13	98	13%	8% to 21%
Jun	0	11	0%	0% to 26%
Jul	0	8	0%	0% to 32%
Aug	1	11	9%	2% to 38%
Sep	0	24	0%	0% to 14%
Oct	4	26	15%	6% to 34%
Nov	1	18	6%	1% to 26%
Dec	19	38	50%	35% to 65%

Peak flowering in Feb. Each bar is the share of Thamnosma montana 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. 531 of 857 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 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.

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.