Colutea arborescens (bladder senna)

Plate 1 figs. a–h · 8 separate observations

Colutea arborescens, photographed by Andrew Skotnicki — fig. a Andrew Skotnicki, CC BY 4.0 / 2022-06-10 / obs. 204913797

Colutea arborescens, photographed by veroalsace — fig. b veroalsace, CC BY-SA 4.0 / obs. 205802525

Colutea arborescens, photographed by Fabien Anthelme — fig. d Fabien Anthelme, CC BY-SA 4.0 / obs. 202160845

Colutea arborescens, photographed by Rafael Medina — fig. e Rafael Medina, CC BY 4.0 / obs. 199707781

Colutea arborescens, photographed by Eleftherios Katsillis — fig. f Eleftherios Katsillis, CC BY 4.0 / obs. 197941762

Colutea arborescens, photographed by Patrick Hacker — fig. g Patrick Hacker, CC BY 4.0 / obs. 176307889

Colutea arborescens, photographed by Josep Gesti — fig. h Josep Gesti, CC BY-SA 4.0 / obs. 171758574

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 14 botanical countries

Native distribution of Colutea arborescens, 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
Albania	ALB	EUROPE
Austria	AUT
Bulgaria	BUL
Czechia-Slovakia	CZE
France	FRA
Germany	GER
Greece	GRC
Hungary	HUN
Italy	ITA
NW. Balkan Pen.	YUG
Romania	ROM
Spain	SPA
Switzerland	SWI
Türkiye-in-Europe	TUE

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 200 in flower of 343 examined

75%

80%

57%

50%

32%

12%

70%

14%

Proportion of examined Colutea arborescens in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	1	4	too few examined
Feb	1	2	too few examined
Mar	2	3	too few examined
Apr	12	16	75%	51% to 90%
May	73	91	80%	71% to 87%
Jun	60	105	57%	48% to 66%
Jul	23	46	50%	36% to 64%
Aug	9	28	32%	18% to 51%
Sep	2	17	12%	3% to 34%
Oct	14	20	70%	48% to 85%
Nov	1	7	14%	3% to 51%
Dec	2	4	too few examined

Peak flowering in May. Each bar is the share of Colutea arborescens 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. 200 of 343 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 4 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 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.

Baguenaudiera arborea Bubani
Colutea arborea Rydb.
Colutea arborescens f. bullata Rehder
Colutea arborescens f. crispa (G.Kirchn.) C.K.Schneid.
Colutea arborescens var. crispa G.Kirchn.
Colutea aurantiaca G.Nicholson
Colutea crocea G.Nicholson
Colutea florida Salisb.
Colutea hirsuta Roth
Colutea hispanica Talavera & Arista
Colutea rubra Medik.
Swartzia remigifera Amshoff

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.