Gentiana affinis (pleated gentian)

Plate 1 figs. a–h · 8 separate observations

Gentiana affinis, photographed by agoldber — fig. a agoldber, CC0 1.0 / 2021-09-12 / obs. 157785587

Gentiana affinis, photographed by Jes Gray — fig. b Jes Gray, CC BY 4.0 / obs. 155110324

Gentiana affinis, photographed by Drew Meyer — fig. c Drew Meyer, CC0 1.0 / obs. 147669423

Gentiana affinis, photographed by Steve Wells — fig. f Steve Wells, CC0 1.0 / obs. 91731375

Gentiana affinis, photographed by Mary Krieger — fig. g Mary Krieger, CC BY 4.0 / obs. 88947392

Gentiana affinis, photographed by Asher P Higgins — fig. h Asher P Higgins, CC BY 4.0 / obs. 52471710

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 20 botanical countries

Native distribution of Gentiana affinis, 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
Alberta	ABT	NORTHERN AMERICA
Arizona	ARI
British Columbia	BRC
California	CAL
Colorado	COL
Idaho	IDA
Manitoba	MAN
Minnesota	MIN
Montana	MNT
Nevada	NEV
New Mexico	NWM
North Dakota	NDA
Northwest Territories	NWT
Oregon	ORE
Saskatchewan	SAS
South Dakota	SDA
Texas	TEX
Utah	UTA
Washington	WAS
Wyoming	WYO

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 188 in flower of 210 examined

80%

93%

92%

82%

78%

Proportion of examined Gentiana affinis in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	0	0	too few examined
Feb	0	0	too few examined
Mar	0	0	too few examined
Apr	0	0	too few examined
May	0	0	too few examined
Jun	4	5	80%	38% to 96%
Jul	67	72	93%	85% to 97%
Aug	82	89	92%	85% to 96%
Sep	28	34	82%	66% to 92%
Oct	7	9	78%	45% to 94%
Nov	0	0	too few examined
Dec	0	1	too few examined

Peak flowering in Jul. Each bar is the share of Gentiana affinis 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. 188 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.

Where it actually grows measured, from 1,368 observations

Condition	5th percentile	Median	95th percentile
Coldest month, mean daily low	-18.0 °C	-11.3 °C	6.3 °C
Warmest month, mean daily high	19.1 °C	23.5 °C	28.0 °C
Annual rainfall	356 mm	534 mm	1,243 mm
Rainfall in the driest quarter	12 mm	60 mm	145 mm

It is found where winters are severely cold. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 1,368 research-grade observations of Gentiana affinis that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one. Climate from CHELSA V2.1 (Karger et al. 2017); occurrences from 10.15468/dl.cgje2x.

Also published as 27 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.

Dasystephana affinis (Griseb.) Rydb.
Dasystephana bigelovii (A.Gray) Rydb.
Dasystephana forwoodii (A.Gray) Rydb.
Dasystephana interrupta (Greene) Rydb.
Dasystephana oregana (Engelm. ex A.Gray) Rydb.
Dasystephana oxyloba Greene
Dasystephana rusbyi (Greene ex Kusn.) Wooton & Standl.
Gentiana affinis subsp. rusbyi (Greene ex Kusn.) Halda
Gentiana affinis var. affinis
Gentiana affinis var. bigelovii (A.Gray) Kusn.
Gentiana affinis var. brachycalyx A.Gray
Gentiana affinis var. forwoodii (A.Gray) Kusn.
Gentiana affinis var. major A.Nelson & J.F.Macbr.
Gentiana affinis var. ovata A.Gray
Gentiana affinis var. parvidentata Kusn.
Gentiana bigelovii A.Gray
Gentiana bigelowii A.Gray
Gentiana forwoodii A.Gray
Gentiana interrupta Greene
Gentiana oregana Engelm. ex A.Gray
Gentiana rusbyi Greene ex Kusn.
Pneumonanthe affinis (Griseb.) Greene
Pneumonanthe bigelovii (A.Gray) Greene
Pneumonanthe forwoodii (A.Gray) Greene

and 3 more.

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.