Coreopsis verticillata (whorled tickseed)

Plate 1 figs. a–h · 8 separate observations

Coreopsis verticillata, photographed by Kathy Richardson — fig. a Kathy Richardson, CC BY 4.0 / 2021-07-26 / obs. 146505608

Coreopsis verticillata, photographed by Eric Schmidt — fig. b Eric Schmidt, CC BY 4.0 / obs. 142832177

Coreopsis verticillata, photographed by Ashwin Srinivasan — fig. c Ashwin Srinivasan, CC BY 4.0 / obs. 87924663

Coreopsis verticillata, photographed by Tyler Ekholm — fig. d Tyler Ekholm, CC BY 4.0 / obs. 80878464

Coreopsis verticillata, photographed by Becky Dill — fig. e Becky Dill, CC0 1.0 / obs. 80825619

Coreopsis verticillata, photographed by Navin Sasikumar — fig. f Navin Sasikumar, CC BY 4.0 / obs. 36432596

Coreopsis verticillata, photographed by ch3chia — fig. g ch3chia, CC BY 4.0 / obs. 24534344

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.

Flowering 198 in flower of 210 examined

85%

96%

98%

100%

95%

Proportion of examined Coreopsis verticillata in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	0	1	too few examined
Feb	0	0	too few examined
Mar	0	0	too few examined
Apr	0	0	too few examined
May	23	27	85%	68% to 94%
Jun	72	75	96%	89% to 99%
Jul	56	57	98%	91% to 100%
Aug	28	28	100%	88% to 100%
Sep	19	20	95%	76% to 99%
Oct	0	2	too few examined
Nov	0	0	too few examined
Dec	0	0	too few examined

Peak flowering in Aug. Each bar is the share of Coreopsis verticillata 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. 198 of 210 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 7 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 verticillata Baill.
Coreopsis verticillata var. verticillata

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.

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. It has no native range either: Kew's checklist does not cover this taxon.