Oenothera pilosellaRaf.

Prairie sundropsmeadow evening primrose

WFO wfo-0001087548 Accepted WFO 2026-06 8 photographs CC0 / CC BY / CC BY-SA

Plate 1 figs. a–h · 8 separate observations

Oenothera pilosella, photographed by Ryan Sorrells
fig. a Ryan Sorrells, CC BY 4.0 / 2022-06-12 / obs. 205834180
Oenothera pilosella, photographed by Ryan Sorrells
fig. b Ryan Sorrells, CC BY 4.0 / obs. 205674509
Oenothera pilosella, photographed by Jacob Friend
fig. c Jacob Friend, CC0 1.0 / obs. 82435850
Oenothera pilosella, photographed by Mike B
fig. d Mike B, CC BY-SA 4.0 / obs. 81246721
Oenothera pilosella, photographed by Mike B
fig. e Mike B, CC BY-SA 4.0 / obs. 80162526
Oenothera pilosella, photographed by Mike B
fig. f Mike B, CC BY-SA 4.0 / obs. 78366835
Oenothera pilosella, photographed by Katie Kucera
fig. g Katie Kucera, CC BY 4.0 / obs. 43368006
Oenothera pilosella, photographed by Katie Kucera
fig. h Katie Kucera, CC BY 4.0 / obs. 43369968

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 18 botanical countries

Regions where Oenothera pilosella is native: Alabama, Arkansas, Illinois, Indiana, Iowa, Kentucky, Louisiana, Michigan, Mississippi, Missouri, New York, Ohio, Oklahoma, Pennsylvania, Tennessee, Virginia, West Virginia, Wisconsin AlabamaArkansasIllinoisIndianaIowaKentuckyLouisianaMichiganMississippiMissouriNew YorkOhioOklahomaPennsylvaniaTennesseeVirginiaWest VirginiaWisconsin
Native distribution of Oenothera pilosella, 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
Alabama ALA NORTHERN AMERICA
Arkansas ARK
Illinois ILL
Indiana INI
Iowa IOW
Kentucky KTY
Louisiana LOU
Michigan MIC
Mississippi MSI
Missouri MSO
New York NWY
Ohio OHI
Oklahoma OKL
Pennsylvania PEN
Tennessee TEN
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 66 in flower of 66 examined

Peak flowering in Jun. Each bar is the share of Oenothera pilosella 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. 66 of 66 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.

Also published as 9 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.

  • Kneiffia fruticosa var. pilosella (Raf.) Britton
  • Kneiffia pilosella A.Heller
  • Kneiffia pratensis Small
  • Kneiffia sumstinei Jenn.
  • Oenothera fruticosa f. hirsuta (Torr. & A.Gray) H.Lév.
  • Oenothera fruticosa var. hirsuta Nutt. ex Torr. & A.Gray
  • Oenothera fruticosa var. pilosella (Raf.) Small & A.Heller
  • Oenothera pilosella f. laevigata E.J.Palmer & Steyerm.
  • Oenothera pratensis (Small) B.L.Rob.

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.