Oenothera rhombipetalaNutt. ex Torr. & A.Gray

Sand primrosefourpoint evening primrose

WFO wfo-0001087552 Accepted WFO 2026-06 8 photographs CC0 / CC BY / CC BY-SA

Plate 1 figs. a–h · 8 separate observations

Oenothera rhombipetala, photographed by Annika Lindqvist
fig. a Annika Lindqvist, CC BY 4.0 / 2021-06-24 / obs. 139666069
Oenothera rhombipetala, photographed by Annika Lindqvist
fig. b Annika Lindqvist, CC BY 4.0 / obs. 139665965
Oenothera rhombipetala, photographed by Owen McElroy
fig. c Owen McElroy, CC0 1.0 / obs. 86056542
Oenothera rhombipetala, photographed by saltyhiker
fig. d saltyhiker, CC BY 4.0 / obs. 83497481
Oenothera rhombipetala, photographed by Kyle M. Simpson
fig. e Kyle M. Simpson, CC BY 4.0 / obs. 83372935
Oenothera rhombipetala, photographed by Eric Knight
fig. f Eric Knight, CC BY 4.0 / obs. 20775678
Oenothera rhombipetala, photographed by Sam Kieschnick
fig. g Sam Kieschnick, CC BY 4.0 / obs. 5086226
Oenothera rhombipetala, photographed by Robert Webster
fig. h Robert Webster, CC BY-SA 4.0 / obs. 62493155

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 13 botanical countries

Regions where Oenothera rhombipetala is native: Arkansas, Colorado, Illinois, Kansas, Michigan, Minnesota, Missouri, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, Wisconsin ArkansasColoradoIllinoisKansasMichiganMinnesotaMissouriNebraskaNew MexicoOklahomaSouth DakotaTexasWisconsin
Native distribution of Oenothera rhombipetala, 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
Arkansas ARK NORTHERN AMERICA
Colorado COL
Illinois ILL
Kansas KAN
Michigan MIC
Minnesota MIN
Missouri MSO
Nebraska NEB
New Mexico NWM
Oklahoma OKL
South Dakota SDA
Texas TEX
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 32 in flower of 32 examined

Peak flowering in Jun. Each bar is the share of Oenothera rhombipetala 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. 32 of 32 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 2 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.

  • Oenothera heterophylla var. rhombipetala (Nutt. ex Torr. & A.Gray) Fosberg
  • Raimannia rhombipetala (Nutt. ex Torr. & A.Gray) Rose ex Britton & A.Br.

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.