Cirsium mohavense (Mojave thistle)

Plate 1 figs. a–h · 8 separate observations

Cirsium mohavense, photographed by Robert Webster — fig. a Robert Webster, CC BY-SA 4.0 / 2022-05-15 / obs. 198041555

Cirsium mohavense, photographed by Steve Matson — fig. c Steve Matson, CC BY 4.0 / obs. 159707352

Cirsium mohavense, photographed by Ciara Hall — fig. d Ciara Hall, CC BY 4.0 / obs. 123369751

Cirsium mohavense, photographed by Jason Eckberg — fig. e Jason Eckberg, CC BY 4.0 / obs. 87153581

Cirsium mohavense, photographed by Millie Basden — fig. g Millie Basden, CC BY 4.0 / obs. 13541755

Cirsium mohavense, photographed by Jim Morefield — fig. h Jim Morefield, CC BY 4.0 / obs. 3892579

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 Cirsium mohavense, 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 81 in flower of 93 examined

13%

100%

94%

100%

92%

88%

Proportion of examined Cirsium mohavense in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	2	3	too few examined
Feb	0	1	too few examined
Mar	2	2	too few examined
Apr	1	8	13%	2% to 47%
May	12	12	100%	76% to 100%
Jun	17	18	94%	74% to 99%
Jul	4	4	too few examined
Aug	3	3	too few examined
Sep	18	18	100%	82% to 100%
Oct	12	13	92%	67% to 99%
Nov	7	8	88%	53% to 98%
Dec	3	3	too few examined

Peak flowering in May. Each bar is the share of Cirsium mohavense 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. 81 of 93 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 6 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.

Also published as 6 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.

Carduus mohavensis Greene
Carduus rusbyi Greene
Cirsium mohavense Davidson & Moxley
Cirsium mohavense subsp. mohavense
Cirsium rusbyi (Greene) Petr.
Cirsium virginense S.L.Welsh

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.