Symphyotrichum laeve(L.) Á.Löve & D.Löve

smooth blue aster

WFO wfo-0000129622 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Symphyotrichum laeve, photographed by Robert Hoard
fig. a Robert Hoard, CC0 1.0 / 2021-11-27 / obs. 170467337
Symphyotrichum laeve, photographed by Eric Schmidt
fig. b Eric Schmidt, CC BY 4.0 / obs. 174661905
Symphyotrichum laeve, photographed by Dilrukshan Priyantha Wijesinghe
fig. c Dilrukshan Priyantha Wijesinghe, CC BY 4.0 / obs. 162865377
Symphyotrichum laeve, photographed by Dilrukshan Priyantha Wijesinghe
fig. d Dilrukshan Priyantha Wijesinghe, CC BY 4.0 / obs. 162757998
Symphyotrichum laeve, photographed by Susan Berry
fig. e Susan Berry, CC0 1.0 / obs. 160709813
Symphyotrichum laeve, photographed by Tom Lazar
fig. f Tom Lazar, CC0 1.0 / obs. 159866708
Symphyotrichum laeve, photographed by Paul Roots
fig. g Paul Roots, CC BY 4.0 / obs. 158040436
Symphyotrichum laeve, photographed by allan5519
fig. h allan5519, CC BY 4.0 / obs. 154407009

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 56 botanical countries

Regions where Symphyotrichum laeve is native: Alabama, Alberta, Arkansas, British Columbia, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Manitoba, Maryland, Massachusetts, Mexico Northeast, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Brunswick, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Ontario, Oregon, Pennsylvania, Québec, Rhode I., Saskatchewan, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming, Yukon AlabamaAlbertaArkansasBritish ColumbiaCaliforniaColoradoConnecticutFloridaGeorgiaIdahoIllinoisIndianaIowaKansasKentuckyLouisianaMaineManitobaMarylandMassachusettsMexico NortheastMichiganMinnesotaMississippiMissouriMontanaNebraskaNevadaNew BrunswickNew HampshireNew JerseyNew MexicoNew YorkNorth CarolinaNorth DakotaOhioOntarioOregonPennsylvaniaQuébecSaskatchewanSouth CarolinaSouth DakotaTennesseeTexasUtahVermontVirginiaWashingtonWest VirginiaWisconsinWyomingYukon DelawareDistrict of ColumbiaRhode I.
Native distribution of Symphyotrichum laeve, 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
Alabama ALA NORTHERN AMERICA
Alberta ABT
Arkansas ARK
British Columbia BRC
California CAL
Colorado COL
Connecticut CNT
Delaware DEL
District of Columbia WDC
Florida FLA
Georgia GEO
Idaho IDA
Illinois ILL
Indiana INI
Iowa IOW
Kansas KAN
Kentucky KTY
Louisiana LOU
Maine MAI
Manitoba MAN
Maryland MRY
Massachusetts MAS
Mexico Northeast MXE
Michigan MIC
Minnesota MIN
Mississippi MSI
Missouri MSO
Montana MNT
Nebraska NEB
Nevada NEV
New Brunswick NBR
New Hampshire NWH
New Jersey NWJ
New Mexico NWM
New York NWY
North Carolina NCA
North Dakota NDA
Ohio OHI
Ontario ONT
Oregon ORE
Pennsylvania PEN
Québec QUE
Rhode I. RHO
Saskatchewan SAS
South Carolina SCA
South Dakota SDA
Tennessee TEN
Texas TEX
Utah UTA
Vermont VER
Virginia VRG
Washington WAS
West Virginia WVA
Wisconsin WIS
Wyoming WYO
Yukon YUK

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 743 in flower of 812 examined

Peak flowering in Dec. Each bar is the share of Symphyotrichum laeve 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. 743 of 812 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 3 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 1,981 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -19.1 °C -11.1 °C -3.5 °C
Warmest month, mean daily high 21.9 °C 25.3 °C 29.0 °C
Annual rainfall 389 mm 685 mm 1,229 mm
Rainfall in the driest quarter 33 mm 69 mm 264 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 1,981 research-grade observations of Symphyotrichum laeve 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 43 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.

  • Aster attenuatus Lindl.
  • Aster attenuatus Lindl.
  • Aster autranii Post
  • Aster bupleurifolius Hort.Monsp. ex Nees
  • Aster concinnus Willd.
  • Aster cyaneus Hoffm.
  • Aster decorus Desf. ex DC.
  • Aster expansus Nees
  • Aster falcidens E.S.Burgess
  • Aster glaucescens Wender. ex Nees
  • Aster glaucus Nees
  • Aster gracilentus Torr. & A.Gray
  • Aster laevigatus Willd.
  • Aster laevis L.
  • Aster laevis f. laevis
  • Aster laevis subsp. geyeri (A.Gray) Piper
  • Aster laevis subsp. laevis
  • Aster laevis var. abbreviatus Lunell
  • Aster laevis var. amplifolius Porter
  • Aster laevis var. cyaneus (Hoffm.) A.Gray
  • Aster laevis var. falcatus Farw.
  • Aster laevis var. geyeri A.Gray
  • Aster laevis var. guadalupensis A.G.Jones
  • Aster laevis var. laevigatus (Willd.) A.Gray

and 19 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.