Erigeron acrisL.

Blue Fleabanebitter fleabane

WFO wfo-0000085388 Accepted WFO 2026-06 8 photographs CC0 / CC BY / CC BY-SA

Plate 1 figs. a–h · 8 separate observations

Erigeron acris, photographed by Pavel Kacl
fig. a Pavel Kacl, CC BY 4.0 / 2022-06-12 / obs. 205802556

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
The New York Botanical Garden
Accession
168401
Filed as
Erigeron acris var. debilis A.Gray
Det. by
A. Cronquist 1945-01-01
Collected
Illegible collector name
Origin
US
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 98 botanical countries

Regions where Erigeron acris is native: Morocco, Afghanistan, Altay, Amur, Buryatiya, China North-Central, China South-Central, China Southeast, Chita, Inner Mongolia, Iran, Iraq, Irkutsk, Japan, Kamchatka, Kazakhstan, Khabarovsk, Kirgizstan, Korea, Krasnoyarsk, Kuril Is., Magadan, Manchuria, Mongolia, North Caucasus, Primorye, Qinghai, Sakhalin, Tadzhikistan, Tibet, Transcaucasus, Türkiye, Turkmenistan, Tuva, Uzbekistan, West Siberia, Xinjiang, Yakutiya, Assam, East Himalaya, India, Myanmar, Nepal, Pakistan, West Himalaya, Austria, Baltic States, Belarus, Bulgaria, Central European Russia, Corse, Czechia-Slovakia, East European Russia, Finland, France, Germany, Great Britain, Greece, Hungary, Ireland, Italy, Krym, Netherlands, North European Russia, Northwest European Russia, Norway, NW. Balkan Pen., Poland, Portugal, Romania, South European Russia, Spain, Sweden, Switzerland, Ukraine, Alaska, Alberta, British Columbia, Colorado, Idaho, Labrador, Maine, Manitoba, Michigan, Minnesota, Montana, New Brunswick, Northwest Territories, Nunavut, Ontario, Oregon, Québec, Saskatchewan, South Dakota, Utah, Washington, Wyoming, Yukon MoroccoAfghanistanAltayAmurBuryatiyaChina North-CentralChina South-CentralChina SoutheastChitaInner MongoliaIranIraqIrkutskJapanKamchatkaKazakhstanKhabarovskKirgizstanKrasnoyarskMagadanManchuriaMongoliaNorth CaucasusPrimoryeQinghaiSakhalinTadzhikistanTibetTranscaucasusTürkiyeTurkmenistanTuvaUzbekistanWest SiberiaXinjiangYakutiyaAssamEast HimalayaIndiaMyanmarNepalPakistanWest HimalayaAustriaBaltic StatesBelarusBulgariaCentral European RussiaCorseCzechia-SlovakiaEast European RussiaFinlandFranceGermanyGreeceHungaryIrelandItalyKrymNetherlandsNorth European RussiaNorthwest European RussiaNorwayNW. Balkan Pen.PolandPortugalRomaniaSouth European RussiaSpainSwedenSwitzerlandUkraineAlaskaAlbertaBritish ColumbiaColoradoIdahoLabradorMaineManitobaMichiganMinnesotaMontanaNew BrunswickNorthwest TerritoriesNunavutOntarioOregonQuébecSaskatchewanSouth DakotaUtahWashingtonWyomingYukon Korea
Native distribution of Erigeron acris, 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. Regions too small to draw at this scale are marked with a dot.
RegionTDWG codeContinent
Afghanistan AFG ASIA-TEMPERATE
Altay ALT
Amur AMU
Buryatiya BRY
China North-Central CHN
China South-Central CHC
China Southeast CHS
Chita CTA
Inner Mongolia CHI
Iran IRN
Iraq IRQ
Irkutsk IRK
Japan JAP
Kamchatka KAM
Kazakhstan KAZ
Khabarovsk KHA
Kirgizstan KGZ
Korea KOR
Krasnoyarsk KRA
Kuril Is. KUR
Magadan MAG
Manchuria CHM
Mongolia MON
North Caucasus NCS
Primorye PRM
Qinghai CHQ
Sakhalin SAK
Tadzhikistan TZK
Tibet CHT
Transcaucasus TCS
Türkiye TUR
Turkmenistan TKM
Tuva TVA
Uzbekistan UZB
West Siberia WSB
Xinjiang CHX
Yakutiya YAK
Austria AUT EUROPE
Baltic States BLT
Belarus BLR
Bulgaria BUL
Central European Russia RUC
Corse COR
Czechia-Slovakia CZE
East European Russia RUE
Finland FIN
France FRA
Germany GER
Great Britain GRB
Greece GRC
Hungary HUN
Ireland IRE
Italy ITA
Krym KRY
Netherlands NET
North European Russia RUN
Northwest European Russia RUW
Norway NOR
NW. Balkan Pen. YUG
Poland POL
Portugal POR
Romania ROM
South European Russia RUS
Spain SPA
Sweden SWE
Switzerland SWI
Ukraine UKR
Alaska ASK NORTHERN AMERICA
Alberta ABT
British Columbia BRC
Colorado COL
Idaho IDA
Labrador LAB
Maine MAI
Manitoba MAN
Michigan MIC
Minnesota MIN
Montana MNT
New Brunswick NBR
Northwest Territories NWT
Nunavut NUN
Ontario ONT
Oregon ORE
Québec QUE
Saskatchewan SAS
South Dakota SDA
Utah UTA
Washington WAS
Wyoming WYO
Yukon YUK
Assam ASS ASIA-TROPICAL
East Himalaya EHM
India IND
Myanmar MYA
Nepal NEP
Pakistan PAK
West Himalaya WHM
Morocco MOR AFRICA

Not drawn on the map: Kuril Is., Great Britain. We hold no public-domain boundary for these regions, so they are listed rather than guessed at.

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 470 in flower of 546 examined

Proportion of examined Erigeron acris in flower, by month
Month In flower Examined Share 95% interval
Jan 0 0 too few examined
Feb 1 1 too few examined
Mar 1 1 too few examined
Apr 0 0 too few examined
May 15 22 68% 47% to 84%
Jun 127 137 93% 87% to 96%
Jul 176 198 89% 84% to 93%
Aug 90 112 80% 72% to 87%
Sep 21 29 72% 54% to 85%
Oct 24 31 77% 60% to 89%
Nov 9 9 100% 70% to 100%
Dec 6 6 100% 61% to 100%

Peak flowering in Nov. Each bar is the share of Erigeron acris 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. 470 of 546 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 4 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 2,051 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -25.7 °C -11.2 °C 1.1 °C
Warmest month, mean daily high 17.7 °C 22.9 °C 26.0 °C
Annual rainfall 406 mm 628 mm 1,030 mm
Rainfall in the driest quarter 34 mm 103 mm 190 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 2,051 research-grade observations of Erigeron acris 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 45 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.

  • Erigeron acer subsp. brachycephalus (H.Lindb.) Hiitonen
  • Erigeron acer subsp. decoloratus (H.Lindb.) Hiitonen
  • Erigeron acer subsp. kamtschaticus (DC.) H.Hara
  • Erigeron acer var. asteroides (Andrz. ex Besser) DC.
  • Erigeron acris subsp. acris
  • Erigeron acris var. asteroides (Andrz. ex Besser) DC.
  • Erigeron acris var. fuscomarginatus Emb. & Maire
  • Erigeron angulosus Gaudin
  • Erigeron angulosus subsp. angulosus
  • Erigeron angulosus var. angulosus
  • Erigeron angulosus var. kamtschaticus (DC.) H.Hara
  • Erigeron angustatus Fries ex Nyman
  • Erigeron asteroides Andrz. ex Besser
  • Erigeron brachycephalus H.Lindb.
  • Erigeron corymbosus Wallr.
  • Erigeron crispulus Borbás
  • Erigeron decoloratus H.Lindb.
  • Erigeron droebachiensis O.F.Müll.
  • Erigeron elongatiformis (Novopokr.) Serg.
  • Erigeron elongatus Ledeb.
  • Erigeron glabratus var. minor Hook.
  • Erigeron intermedius Rchb. ex Nyman
  • Erigeron kamtschaticus DC.
  • Erigeron kamtschaticus var. kamtschaticus

and 21 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.