Cirsium pumilumSpreng.

pasture thistle

WFO wfo-0000125166 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Cirsium pumilum, photographed by Lynn Harper
fig. a Lynn Harper, CC0 1.0 / 2021-07-15 / obs. 143834892

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
Smithsonian, US National Herbarium
Accession
US 785639
Filed as
Cirsium pumilum (Nutt.) Spreng.
Det. by
Ownbey, G. B.
Collected
E. Steele 1902-06-22
Origin
US
The sheet
View the digitised specimen (CC0 1.0)

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 23 botanical countries

Regions where Cirsium pumilum is native: Connecticut, Delaware, Illinois, Indiana, Iowa, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, New Jersey, New York, North Carolina, Ohio, Ontario, Pennsylvania, Rhode I., South Carolina, Vermont, Virginia, West Virginia, Wisconsin ConnecticutIllinoisIndianaIowaMaineMarylandMassachusettsMichiganMinnesotaNew HampshireNew JerseyNew YorkNorth CarolinaOhioOntarioPennsylvaniaSouth CarolinaVermontVirginiaWest VirginiaWisconsin DelawareRhode I.
Native distribution of Cirsium pumilum, 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
Connecticut CNT NORTHERN AMERICA
Delaware DEL
Illinois ILL
Indiana INI
Iowa IOW
Maine MAI
Maryland MRY
Massachusetts MAS
Michigan MIC
Minnesota MIN
New Hampshire NWH
New Jersey NWJ
New York NWY
North Carolina NCA
Ohio OHI
Ontario ONT
Pennsylvania PEN
Rhode I. RHO
South Carolina SCA
Vermont VER
Virginia VRG
West Virginia WVA
Wisconsin WIS

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 164 in flower of 274 examined

Proportion of examined Cirsium pumilum 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 1 too few examined
Apr 0 6 0% 0% to 39%
May 0 16 0% 0% to 19%
Jun 48 68 71% 59% to 80%
Jul 88 110 80% 72% to 86%
Aug 21 30 70% 52% to 83%
Sep 6 28 21% 10% to 40%
Oct 1 10 10% 2% to 40%
Nov 0 5 0% 0% to 43%
Dec 0 0 too few examined

Peak flowering in Jul. Each bar is the share of Cirsium pumilum 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. 164 of 274 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 586 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -12.0 °C -6.5 °C -0.2 °C
Warmest month, mean daily high 20.7 °C 26.1 °C 31.1 °C
Annual rainfall 844 mm 1,178 mm 1,519 mm
Rainfall in the driest quarter 132 mm 250 mm 318 mm

It is found where winters bring hard frost. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 586 research-grade observations of Cirsium pumilum 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 18 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.

  • Carduus hillii (Canby) Porter
  • Carduus odoratus Porter
  • Carduus odoratus Muhl.
  • Carduus pumilus Nutt.
  • Cirsium hillii Fernald
  • Cirsium hillii f. albiflorum E.G.Voss
  • Cirsium hillii f. hillii
  • Cirsium odoratum (Barton) Petr.
  • Cirsium pumilum f. albiflorum Scoggan
  • Cirsium pumilum f. candidum Fernald
  • Cirsium pumilum f. fultius Fernald
  • Cirsium pumilum f. pumilum
  • Cirsium pumilum subsp. hillii (Canby) R.J.Moore & Frankton
  • Cirsium pumilum subsp. pumilum
  • Cnicus hillii Canby
  • Cnicus odaratus Muhl. ex Steud.
  • Cnicus odoratus Britton, Sterns & Poggenb.
  • Cnicus pumilus Torr.

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.