Coptis aspleniifolia (fernleaf goldthread)

Plate 1 figs. a–h · 8 separate observations

Coptis aspleniifolia, photographed by Braden J. Judson — fig. a Braden J. Judson, CC0 1.0 / 2022-05-04 / obs. 197680372

Coptis aspleniifolia, photographed by Randal — fig. c Randal, CC0 1.0 / obs. 190433562

Coptis aspleniifolia, photographed by Bruce Slater — fig. d Bruce Slater, CC BY 4.0 / obs. 153682089

Coptis aspleniifolia, photographed by Ellyne Geurts — fig. e Ellyne Geurts, CC0 1.0 / obs. 166714416

Coptis aspleniifolia, photographed by J Straka — fig. f J Straka, CC BY 4.0 / obs. 152038874

Coptis aspleniifolia, photographed by Matt Muir — fig. g Matt Muir, CC BY 4.0 / obs. 143790109

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 3 botanical countries

Native distribution of Coptis aspleniifolia, 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
Alaska	ASK	NORTHERN AMERICA
British Columbia	BRC
Washington	WAS

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 139 in flower of 599 examined

23%

80%

74%

10%

Proportion of examined Coptis aspleniifolia in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	0	14	0%	0% to 22%
Feb	0	7	0%	0% to 35%
Mar	3	13	23%	8% to 50%
Apr	67	84	80%	70% to 87%
May	51	69	74%	62% to 83%
Jun	17	164	10%	7% to 16%
Jul	1	91	1%	0% to 6%
Aug	0	75	0%	0% to 5%
Sep	0	28	0%	0% to 12%
Oct	0	23	0%	0% to 14%
Nov	0	8	0%	0% to 32%
Dec	0	23	0%	0% to 14%

Peak flowering in Apr. Each bar is the share of Coptis aspleniifolia 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. 139 of 599 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 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.

Chrysocoptis aspleniifolia Nutt.
Coptis aspleniifolia var. biternata Huth

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.
USDA PLANTS Database. common name, checklist symbol COAS. public domain. 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.