Oenothera oakesiana(A.Gray) J.W.Robbins ex S.Watson

Oakes' evening primrose

WFO wfo-0000389683 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Oenothera oakesiana, photographed by Reuven Martin
fig. a Reuven Martin, CC0 1.0 / 2020-09-11 / obs. 94712787
Oenothera oakesiana, photographed by Reuven Martin
fig. b Reuven Martin, CC0 1.0 / obs. 50178267
Oenothera oakesiana, photographed by Reuven Martin
fig. c Reuven Martin, CC0 1.0 / obs. 22488712
Oenothera oakesiana, photographed by Reuven Martin
fig. d Reuven Martin, CC0 1.0 / obs. 11233713
Oenothera oakesiana, photographed by Bonnie Semmling
fig. e Bonnie Semmling, CC BY 4.0 / obs. 160215812
Oenothera oakesiana, photographed by Carol Ann McCormick
fig. f Carol Ann McCormick, CC BY 4.0 / obs. 149465447
Oenothera oakesiana, photographed by Derek
fig. g Derek, CC BY 4.0 / obs. 23683795
Oenothera oakesiana, photographed by John Brew
fig. h John Brew, CC BY 4.0 / obs. 29432238

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 2535172
Filed as
Oenothera oakesiana (A.Gray) J.W.Robbins ex S.Watson
Det. by
Dietrich, W.
Collected
Fr. Marie-Victorin & Rolland-Germain 1935-08-26
Origin
CA
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 26 botanical countries

Regions where Oenothera oakesiana is native: Connecticut, Delaware, District of Columbia, Illinois, Indiana, Kentucky, Maine, Manitoba, Maryland, Massachusetts, Michigan, Minnesota, New Brunswick, New Hampshire, New Jersey, New York, Nova Scotia, Ohio, Ontario, Pennsylvania, Prince Edward I., Québec, Rhode I., Vermont, Virginia, Wisconsin ConnecticutIllinoisIndianaKentuckyMaineManitobaMarylandMassachusettsMichiganMinnesotaNew BrunswickNew HampshireNew JerseyNew YorkNova ScotiaOhioOntarioPennsylvaniaPrince Edward I.QuébecVermontVirginiaWisconsin DelawareDistrict of ColumbiaRhode I.
Native distribution of Oenothera oakesiana, 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
District of Columbia WDC
Illinois ILL
Indiana INI
Kentucky KTY
Maine MAI
Manitoba MAN
Maryland MRY
Massachusetts MAS
Michigan MIC
Minnesota MIN
New Brunswick NBR
New Hampshire NWH
New Jersey NWJ
New York NWY
Nova Scotia NSC
Ohio OHI
Ontario ONT
Pennsylvania PEN
Prince Edward I. PEI
Québec QUE
Rhode I. RHO
Vermont VER
Virginia VRG
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.

Where it actually grows measured, from 189 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -15.0 °C -8.6 °C -0.7 °C
Warmest month, mean daily high 19.8 °C 23.9 °C 26.7 °C
Annual rainfall 543 mm 985 mm 1,290 mm
Rainfall in the driest quarter 87 mm 180 mm 283 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 189 research-grade observations of Oenothera oakesiana 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.

Also published as 47 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 ammophila Focke
  • Oenothera ammophila subsp. germanica (Boedijn) Renner
  • Oenothera ammophila var. germanica (Boedijn) Renner
  • Oenothera ammophila var. rhodoneura Renner
  • Oenothera ammophiloides R.R.Gates & Catches.
  • Oenothera ammophiloides var. angustifolia R.R.Gates
  • Oenothera ammophiloides var. laurensis R.R.Gates
  • Oenothera atrovirens var. ostreae (A.H.Sturtev.) R.R.Gates
  • Oenothera biennis f. stenopetala (E.P.Bicknell) B.Boivin
  • Oenothera biennis var. oakesiana A.Gray
  • Oenothera canovirens var. cymatilis (Bartlett) R.R.Gates
  • Oenothera cruciata var. stenopetala (E.P.Bicknell) Fernald
  • Oenothera cymatilis Bartlett
  • Oenothera deflexa var. bracteata R.R.Gates
  • Oenothera disjuncta Boedijn
  • Oenothera eriensis R.R.Gates
  • Oenothera eriensis var. niagarensis (R.R.Gates) R.R.Gates
  • Oenothera eriensis var. repandodentata (R.R.Gates) R.R.Gates
  • Oenothera germanica Boedijn
  • Oenothera insignis Bartlett
  • Oenothera laevigata var. rubripunctata R.R.Gates
  • Oenothera leucophylla R.R.Gates
  • Oenothera litorea Bartlett
  • Oenothera magdalena R.R.Gates

and 23 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.