Bidens subalternans

Plate 1 figs. a–h · 8 separate observations

Bidens subalternans, photographed by Lauu — fig. c Lauu, CC BY 4.0 / obs. 197885205

Bidens subalternans, photographed by Eduardo Luis Beltrocco — fig. d Eduardo Luis Beltrocco, CC BY 4.0 / obs. 196742924

Bidens subalternans, photographed by Quentin Groom — fig. f Quentin Groom, CC0 1.0 / obs. 168194075

Bidens subalternans, photographed by Josep Gesti — fig. g Josep Gesti, CC BY-SA 4.0 / obs. 167713653

Bidens subalternans, photographed by Tim Johnson — fig. h Tim Johnson, CC BY 4.0 / obs. 161467545

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 7 botanical countries

Native distribution of Bidens subalternans, 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
Argentina Northeast	AGE	SOUTHERN AMERICA
Argentina Northwest	AGW
Bolivia	BOL
Brazil South	BZS
Chile North	CLN
Paraguay	PAR
Uruguay	URU

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 74 in flower of 134 examined

88%

68%

67%

43%

61%

45%

Proportion of examined Bidens subalternans in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	1	4	too few examined
Feb	3	3	too few examined
Mar	7	8	88%	53% to 98%
Apr	13	19	68%	46% to 85%
May	6	9	67%	35% to 88%
Jun	0	4	too few examined
Jul	1	4	too few examined
Aug	2	4	too few examined
Sep	9	21	43%	24% to 63%
Oct	22	36	61%	45% to 75%
Nov	10	22	45%	27% to 65%
Dec	0	0	too few examined

Peak flowering in Mar. Each bar is the share of Bidens subalternans 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. 74 of 134 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 2 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.

Bidens platensis Manganaro
Bidens quadrangularis DC.

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.
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.