Comastoma tenellum(Rottb.) Toyok.

Dane's dwarf gentianDane's dwarfgentianLapland gentianSamiland-Gentianslender gentian

WFO wfo-0000616005 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Comastoma tenellum, photographed by kfa
fig. a kfa, CC0 1.0 / 2021-08-31 / obs. 154438548

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.

The specimen a real sheet, in a real collection

Herbarium
Royal Botanic Gardens, Kew
Accession
K005058451
Filed as
Comastoma tenellum (Rottb.) Toyok.
Det. by
not recorded on this sheet
Collected
Sørensen, T. 1932-07-06
Origin
GL
The sheet
View the digitised specimen (CC BY 4.0)

A real pressed plant, in a real collection, under the accession number above. Not an illustration of one. The holding institution does not serve this sheet’s image to third parties, so there is no photograph here. The record is real and the link goes to it. Where we hold no openly licensed sheet for a species this section is simply absent, and where a sheet never recorded who determined it, that field stays empty rather than being filled in. Roughly half of all herbarium sheets never recorded a determiner, which is ordinary.

Native range 54 botanical countries

Regions where Comastoma tenellum is native: Morocco, Altay, Buryatiya, Inner Mongolia, Irkutsk, Kamchatka, Kazakhstan, Khabarovsk, Kirgizstan, Krasnoyarsk, Magadan, Mongolia, Tadzhikistan, Tibet, Tuva, West Siberia, Xinjiang, Yakutiya, East Himalaya, Nepal, West Himalaya, Austria, Czechia-Slovakia, Finland, France, Germany, Iceland, North European Russia, Norway, Poland, Romania, Spain, Svalbard, Sweden, Switzerland, Ukraine, Alaska, Arizona, California, Colorado, Greenland, Idaho, Montana, Nevada, New Mexico, Northwest Territories, Nunavut, Ontario, Oregon, Québec, Utah, Washington, Wyoming, Yukon MoroccoAltayBuryatiyaInner MongoliaIrkutskKamchatkaKazakhstanKhabarovskKirgizstanKrasnoyarskMagadanMongoliaTadzhikistanTibetTuvaWest SiberiaXinjiangYakutiyaEast HimalayaNepalWest HimalayaAustriaCzechia-SlovakiaFinlandFranceGermanyIcelandNorth European RussiaNorwayPolandRomaniaSpainSvalbardSwedenSwitzerlandUkraineAlaskaArizonaCaliforniaColoradoGreenlandIdahoMontanaNevadaNew MexicoNorthwest TerritoriesNunavutOntarioOregonQuébecUtahWashingtonWyomingYukon
Native distribution of Comastoma tenellum, 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.
RegionTDWG codeContinent
Alaska ASK NORTHERN AMERICA
Arizona ARI
California CAL
Colorado COL
Greenland GNL
Idaho IDA
Montana MNT
Nevada NEV
New Mexico NWM
Northwest Territories NWT
Nunavut NUN
Ontario ONT
Oregon ORE
Québec QUE
Utah UTA
Washington WAS
Wyoming WYO
Yukon YUK
Altay ALT ASIA-TEMPERATE
Buryatiya BRY
Inner Mongolia CHI
Irkutsk IRK
Kamchatka KAM
Kazakhstan KAZ
Khabarovsk KHA
Kirgizstan KGZ
Krasnoyarsk KRA
Magadan MAG
Mongolia MON
Tadzhikistan TZK
Tibet CHT
Tuva TVA
West Siberia WSB
Xinjiang CHX
Yakutiya YAK
Austria AUT EUROPE
Czechia-Slovakia CZE
Finland FIN
France FRA
Germany GER
Iceland ICE
North European Russia RUN
Norway NOR
Poland POL
Romania ROM
Spain SPA
Svalbard SVA
Sweden SWE
Switzerland SWI
Ukraine UKR
East Himalaya EHM ASIA-TROPICAL
Nepal NEP
West Himalaya WHM
Morocco MOR AFRICA

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 36 in flower of 37 examined

Proportion of examined Comastoma tenellum 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 1 1 too few examined
Jul 18 18 100% 82% to 100%
Aug 16 17 94% 73% to 99%
Sep 0 0 too few examined
Oct 1 1 too few examined
Nov 0 0 too few examined
Dec 0 0 too few examined

Peak flowering in Jul. Each bar is the share of Comastoma tenellum 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. 36 of 37 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 10 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 383 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -33.3 °C -17.9 °C -11.4 °C
Warmest month, mean daily high 9.8 °C 13.9 °C 19.6 °C
Annual rainfall 282 mm 1,134 mm 2,118 mm
Rainfall in the driest quarter 11 mm 166 mm 404 mm

It is found where winters are arctic. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 383 research-grade observations of Comastoma tenellum 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 40 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.

  • Amarella monantha (A.Nelson) Rydb.
  • Cicendia glacialis Raf.
  • Cicendia tenella (Rottb.) Raf.
  • Comastoma boreale (Bunge) T.N.Ho ex Omer
  • Comastoma dichotomum (Pall.) Holub
  • Eyrythalia dichotoma (Pall.) Bercht. & J.Presl
  • Eyrythalia glacialis Bercht. & J.Presl
  • Eyrythalia nana Borkh.
  • Eyrythalia pedunculata D.Don
  • Eyrythalia tenella (Rottb.) H.Buek
  • Gentiana borealis Bunge
  • Gentiana dichotoma Pall.
  • Gentiana fimbriata Vitman
  • Gentiana glacialis Vill.
  • Gentiana islandica Joannei ex Schult.
  • Gentiana koenigii Gunnerus
  • Gentiana monantha A.Nelson
  • Gentiana nivalis Poir.
  • Gentiana oederi Sol. ex Bab.
  • Gentiana tenella Rottb.
  • Gentiana tenella f. alba J.Rousseau & Raymond
  • Gentiana tenella var. monantha (A.Nelson) J.Rousseau
  • Gentiana tenella var. occidentalis J.Rousseau & Raymond
  • Gentiana tenella var. sikkimensis C.B.Clarke

and 16 more.

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
  4. 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.