Encelia frutescens (button brittlebush)

Plate 1 figs. a–h · 8 separate observations

Encelia frutescens, photographed by Craig Martin — fig. a Craig Martin, CC0 1.0 / 2022-02-28 / obs. 181112410

Encelia frutescens, photographed by nmoorhatch — fig. b nmoorhatch, CC BY 4.0 / obs. 161983328

Encelia frutescens, photographed by Bob Miller — fig. c Bob Miller, CC BY 4.0 / obs. 110078553

Encelia frutescens, photographed by A.J. Tarnas — fig. e A.J. Tarnas, CC0 1.0 / obs. 30389566

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 Encelia frutescens, 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 Northeast	MXE
Mexico Northwest	MXN
Nevada	NEV

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 218 in flower of 245 examined

72%

89%

93%

97%

100%

89%

74%

93%

Proportion of examined Encelia frutescens in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	18	25	72%	52% to 86%
Feb	25	28	89%	73% to 96%
Mar	50	54	93%	82% to 97%
Apr	37	38	97%	87% to 100%
May	7	7	100%	65% to 100%
Jun	0	0	too few examined
Jul	1	1	too few examined
Aug	1	1	too few examined
Sep	6	6	100%	61% to 100%
Oct	8	9	89%	56% to 98%
Nov	23	31	74%	57% to 86%
Dec	42	45	93%	82% to 98%

Peak flowering in May. Each bar is the share of Encelia frutescens 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. 218 of 245 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 3 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.

Encelia frutescens f. frutescens
Encelia frutescens f. ovata H.M.Hall
Encelia frutescens subsp. frutescens
Encelia frutescens subsp. glandulosa C.Clark
Encelia frutescens var. frutescens
Simsia frutescens A.Gray

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.