oenothera

The species vary in size from small alpine plants 10 centimeters tall, such as O. acaulis from Chile, to vigorous lowland species growing to 3 meters, such as O. stubbei from Mexico. The leaves form a basal rosette at ground level and spiral up to the flowering stems. The blades are dentate or deeply lobed (pinnatifid). The flowers of many species open in the evening, hence the name "evening primrose". They may open in under a minute. Most species have yellow flowers, but some have white, purple, pink, or red. Most native desert species are white. Oenothera caespitosa, a species of western North America, produces white flowers that turn pink with age.[http://www.npwrc.usgs.gov/resource/plants/wildflwr/species/oenocaes.htm Gumbo Lily (Oenothera caespitosa).] Native Wildflowers of the North Dakota Grasslands. USGS Northern Prairie Wildlife Research Center.

One of the most distinctive features of the flower is the stigma, which has four branches in an X shape.{{cite book | title=A Field Guide to Wildflowers of Northeastern and North-central North America | author=Peterson, R. T. and M. McKenny | isbn=978-0-395-91172-3 | year=1968 | publisher=Houghton Mifflin | location=Boston | url-access=registration | url=https://archive.org/details/fieldguidetowild00roge }}

File:Plant Oenothera biennis evening primrose 11 on black L Plymouth Mass USA D 210714.jpg

Oenothera flowers are pollinated by insects, such as moths and bees. Like many other members of the Onagraceae, however, the pollen grains are loosely held together by viscin threads, so only insects that are morphologically specialized to gather this pollen can effectively pollinate the flowers. Bees with typical scopa cannot hold it. Also, the flowers open at a time when most bee species are inactive, so the bees which visit Oenothera are generally vespertine temporal specialists: bees that forage in the evening. The seeds ripen from late summer to fall.

Oenothera are used as food plants by the larvae of some Lepidoptera species, including the large white-lined sphinx (Hyles lineata).{{Cite web|url=https://www.butterfliesandmoths.org/species/Hyles-lineata|title=White-lined Sphinx Hyles lineata (Fabricius, 1775)|website=Butterflies and Moths of North America|language=en|access-date=2017-11-14}} The flower moths Schinia felicitata and S. florida both feed exclusively on the genus, and the former is limited to O. deltoides.

In the wild, some species of evening primrose act as primary colonizers, quickly appearing in recently cleared areas. They germinate in disturbed soils, and can be found in habitat types such as dunes, roadsides, railway embankments, and waste areas. They are often casual and are eventually out competed by other species.

Based on observations of evening primroses (O. drummondii), a study discovered that within minutes of sensing the sound waves of nearby bee wings through flower petals, the concentration of the sugar in the plant's nectar was increased by an average of 20 percent. Experiments were also conducted on flowers with the petals removed. No change in nectar production was noted, indicating that it is indeed the flowers that have the job of the ears.

Lay summary:

{{Cite web|url=https://www.sciencealert.com/flowers-may-not-have-ears-but-they-can-still-technically-hear-say-scientists|title=Plants May Not Have Ears, But They Can 'Hear' Way Better Than We Thought|last=Nield|first=David|date=January 19, 2019|website=Science Alert}}

{{cite journal|year=2019|publisher=John Wiley & Sons Ltd.|id=French National Centre for Scientific Research (CNRS)|last1=Veits|first1=Marine|last2=Khait|first2=Itzhak|last3=Obolski|first3=Uri|last4=Zinger|first4=Eyal|last5=Boonman|first5=Arjan|last6=Goldshtein|first6=Aya|last7=Saban|first7=Kfir|last8=Seltzer|first8=Rya|last9=Ben-Dor|first9=Udi|last10=Estlein|first10=Paz|last11=Kabat|first11=Areej|last12=Peretz|first12=Dor|last13=Ratzersdorfer|first13=Ittai|last14=Krylov|first14=Slava|last15=Chamovitz|first15=Daniel|last16=Sapir|first16=Yuval|last17=Yovel|first17=Yossi|last18=Hadany|first18=Lilach|journal=Ecology Letters|issn=1461-023X|title=Flowers respond to pollinator sound within minutes by increasing nectar sugar concentration|volume=22|issue=9|doi=10.1111/ele.13331|pages=1483–1492|pmid=31286633 |pmc=6852653 |bibcode=2019EcolL..22.1483V }}

Veits is cited by many reviews:

{{cite journal|year=2020|publisher=John Wiley & Sons Ltd.|last1=Kumar|first1=A.|last2=Memo|first2=M.|last3=Mastinu|first3=A.|title=Plant behaviour: an evolutionary response to the environment?|journal=Plant Biology|volume=22|issue=6issn=1435–8603|doi=10.1111/plb.13149|pages=961–970|s2cid=219902795|pmid=32557960|bibcode=2020PlBio..22..961K }}

{{cite journal|year=2019|publisher=Frontiers Media SA|journal=Frontiers in Ecology and Evolution|issn=2296-701X|last1=Virant-Doberlet|first1=Meta|last2=Kuhelj|first2=Anka|last3=Polajnar|first3=Jernej|last4=Šturm|first4=Rok|title=Predator-Prey Interactions and Eavesdropping in Vibrational Communication Networks|volume=7|page=203 |doi=10.3389/fevo.2019.00203|s2cid=173992538 |doi-access=free |bibcode=2019FrEEv...7..203V |hdl=20.500.12556/DiRROS-20126|hdl-access=free}}

{{cite journal|year=2019|publisher=Elsevier BV|journal=Seminars in Cell & Developmental Biology|last1=Khait|first1=I.|last2=Obolski|first2=U.|last3=Yovel|first3=Y.|last4=Hadany|first4=L.|title=Sound perception in plants|volume=92|issn=1084-9521|doi=10.1016/j.semcdb.2019.03.006|pages=134–138|s2cid=106407725|pmid=30965110}}

Biorxiv:

{{cite journal|year=2018|publisher=Cold Spring Harbor Laboratory (CSHL)|journal=bioRxiv|last1=Veits|first1=Marine|last2=Khait|first2=Itzhak|last3=Obolski|first3=Uri|last4=Zinger|first4=Eyal|last5=Boonman|first5=Arjan|last6=Goldshtein|first6=Aya|last7=Saban|first7=Kfir|last8=Ben-Dor|first8=Udi|last9=Estlein|first9=Paz|last10=Kabat|first10=Areej|last11=Peretz|first11=Dor|last12=Ratzersdorfer|first12=Ittai|last13=Krylov|first13=Slava|last14=Chamovitz|first14=Daniel|last15=Sapir|first15=Yuval|last16=Yovel|first16=Yossi|last17=Hadany|first17=Lilach|title=Flowers respond to pollinator sound within minutes by increasing nectar sugar concentration|doi=10.1101/507319|s2cid=92674047 }}

The genus Oenothera may have originated in Mexico and Central America,{{cite journal|title=An outline of the systematics of Oenothera subsect. Euoenothera (Onagraceae)|journal=Systematic Botany|author=Raven, P. H.|volume=4|issue=3|pages=242–252|doi= 10.2307/2418422|year=1979|jstor=2418422|bibcode=1979SysBo...4..242R |display-authors=etal|author-link=Peter H. Raven}}{{cite book |author=Dietrich, W.|title=Systematics of Oenothera section Oenothera subsection Oenothera (Onagraceae)|publisher=The American Society of Plant Taxonomists |location=Laramie|year=1997 |isbn=978-0-912861-50-0 |display-authors=etal}} and spread farther north in North America and into South America. With the advent of international travel, species are now found in most temperate regions of the world. In Europe alone there are about 70 introduced species of Oenothera. During the Pleistocene era a succession of ice ages swept down across North America, with intervening warm periods. This occurred four times, and the genus experienced four separate waves of colonization, each hybridizing with the survivors of previous waves.{{cite book |author=Cleland, R. E.|title=Oenothera - Cytogenetics and evolution |publisher=Academic Press |location=Boston |year=1972 |isbn=978-0-12-176450-0 |author-link=Ralph E. Cleland }} This formed the present-day subsection Euoenothera. The group is genetically and morphologically diverse and the species are largely interfertile, so the species boundaries have been disputed amongst taxonomists.{{cite journal|title=The classification of subsection Oenothera (section Oenothera, Oenothera L., Onagraceae)|journal=Feddes Repertorium |year=1985|author= Rostanski, K.|volume=96|issue=1–2|pages=3–14|doi=10.1002/fedr.4910960103|doi-access=free}}

{{further|Mutationism}}

File:Hugo de Vries (1848-1935), by Thérèse Schwartze (1851-1918).jpg, making a painting of an evening primrose, which had apparently produced new forms by large mutations in his experiments, by Thérèse Schwartze, 1918]]

The pattern of repeated colonizations resulted in a unique genetic conformation in the Euoenothera whereby the chromosomes at meiosis can form circles rather than pairs. This is the result of several reciprocal translocations between chromosomes such that the pairing occurs only at the tips. This phenomenon apparently has non-Mendelian genetic consequences; with this mode of chromosome segregation and a system of balanced-lethal genes, genetic recombination is prevented and the plants display the hybrid vigor of heterosis.{{cite journal |journal=Genetics |volume=180 |issue=3 |pages=1289–1306 |year=2008 |author=Rauwolf, U. |title=Molecular marker systems for Oenothera genetics |doi=10.1534/genetics.108.091249 |pmid=18791241 |pmc=2581935 |display-authors=etal}} This resulted in the evolution of many sympatric races in North America east of the Rocky Mountains. Analysis of the cytology of these races and of artificial hybrids between them increased understanding of the genetic and geographic evolution of the Euoenothera. This subject was a major area of genetic research during the first half of the 20th century.{{cite book |author=Cleland, R. E. |title=Oenothera - Cytogenetics and Evolution |publisher=Academic Press |location=Boston |year=1972 |isbn=978-0-12-176450-0}}{{cite book |author=Harte, C. |title=Oenothera - Contributions of a Plant to Biology |publisher=Springer-Verlag |location=Berlin |year=1994 |isbn=978-3-540-53114-2}}

The appearance of sudden changes in Oenothera lamarckiana led the pioneering geneticist Hugo de Vries to propose what he called "mutation theory" in 1901 (Mutationstheorie in the German the original article was written in).de Vries, Hugo. Die Mutationstheorie. Versuche und Beobachtungen über die Entstehung von Arten im Pflanzenreich (in German), Leipzig, Veit & Comp., 1901-03. This asserted that speciation was driven by sudden large mutations able to produce new varieties in a single step. The understanding that the observed changes in hybrids of the plant were caused by chromosome duplications (polyploidy) rather than gene mutation did not come until much later.{{cite book |last=Endersby |first=Jim |title=A Guinea Pig's History of Biology |publisher=Harvard University Press |year=2007 |isbn=978-0-674-02713-8 |pages=148–162, 202–205}}{{cite journal |last1=Ramsey |first1=Justin |last2=Ramsey |first2=Tara S. |title=Ecological studies of polyploidy in the 100 years following its discovery |journal=Phil. Trans. R. Soc. Lond. B |date=August 2014 |volume=5 |issue=369 |pages=898–900 |doi=10.1098/rstb.2013.0352 |pmid=24958925 |pmc=4071525 }}

{{also|List of Oenothera species}}

Evening primroses were originally assigned to the genus Onagra, which gave the family Onagraceae its name. Onagra '[food of] onager' was first used in botany in 1587, and in English in Philip Miller's 1754 Gardeners Dictionary: Abridged. The modern name Oenothera was published by Carolus Linnaeus in his Systema Naturae. Its etymology is uncertain, but it is believed to be derived from the Greek words οίνος θήρα (oinos thera) 'wine seeker'.{{cite book |url=https://books.google.com/books?id=NJ6PyhVuecwC |title=The Names of Plants |first=D. |last=Gledhill |edition=4 |publisher=Cambridge University Press |isbn=978-0-521-86645-3 |year=2008 |page=278}}

The genus is divided into 18 sections and additionally into several subsections and series.

Certain Oenothera plants have edible parts. The roots of O. biennis are reportedly edible in young plants. So are the flowers which have a sweet, crunchy taste. [http://www.oardc.ohio-state.edu/weedguide/singlerecord.asp?id=520 Oenothera biennis.] Ohio Perennial and Biennial Weed Guide. The Ohio State University Extension.

The common evening primrose, O. biennis, is commonly sold as a dietary supplement in capsules containing the seed oil.{{cite web |title=Evening primrose oil |url=https://www.nccih.nih.gov/health/evening-primrose-oil |publisher=National Center for Complementary and Integrative Health, US National Institutes of Health |access-date=24 June 2020 |date=1 September 2016}} The main phytochemical in this evening primrose seed oil is gamma-linolenic acid.

There is no high-quality scientific evidence that O. biennis or evening primrose oil has any effect on human diseases or promotion of health,{{cite journal|vauthors=Bamford JT, Ray S, Musekiwa A, van Gool C, Humphreys R, Ernst E |year=2013 |pmid=23633319 |title=Oral evening primrose oil and borage oil for eczema |journal=Cochrane Database of Systematic Reviews |volume=4 |issue=4 |id=CD004416 |display-authors=etal |doi=10.1002/14651858.CD004416.pub2 |pages=CD004416|pmc=8105655 }} and specifically no evidence that it is effective to treat atopic dermatitis or cancer.{{cite web |url=http://www.cancer.org/treatment/treatmentsandsideeffects/complementaryandalternativemedicine/pharmacologicalandbiologicaltreatment/gamma-linolenic-acid|title=Gamma Linolenic Acid |publisher=American Cancer Society |date=13 May 2010 |access-date=13 August 2013}} Research indicates that orally-administered evening primrose oil does not relieve symptoms of premenstrual syndrome,{{cite web |url=https://nccih.nih.gov/health/eveningprimrose |title=Evening primrose oil |date=2015-02-14 |publisher=National Center for Complementary and Integrative Health}}{{cite journal |last=Douglas |first=Sue |title=Premenstrual syndrome. Evidence-based treatment in family practice |journal=Canadian Family Physician |date=November 2002 |volume=48 |issue=11 |pages=1789–1797 |pmid=12489244 |pmc=2213956}} and does not have an effect on shortening the length of pregnancy or labor.{{cite journal |last=McFarlin |first=B. L. |author2=Gibson, M. H. |author3=O'Rear, J. |author4=Harman, P. |title=A national survey of herbal preparation use by nurse-midwives for labor stimulation |journal=J Nurse-Midwifery |year=1999 |volume=44 |issue=3 |pages=205–216 |pmid=10380441 |doi=10.1016/S0091-2182(99)00037-3}}{{cite journal |last=Tenore |first=Josie L. |title=Methods for Cervical Ripening and Induction of Labor |journal=American Family Physician |date=15 May 2003 |volume=67 |issue=10 |pages=2123–2128 |pmid=12776961 |url=http://www.aafp.org/afp/2003/0515/p2123.html}}{{cite journal |last=Adair |first=C. |title=Cervical Ripening And Labor Induction Nonpharmacologic Approaches to Cervical Priming and Labor Induction |journal=Clinical Obstetrics & Gynecology |date=September 2000 |volume=43 |issue=3 |pages=447–454 |pmid=10949749 |url=https://dx.doi.org/10.1097/00003081-200009000-00005 |doi=10.1097/00003081-200009000-00005|url-access=subscription }}{{cite journal |last=Dove |first=Dorinda |author2=Peter Johnson |title=Oral evening primrose oil: Its effect on length of pregnancy and selected intrapartum outcomes in low-risk nulliparous women |journal=Journal of Nurse-Midwifery |date=May–June 1999 |volume=44 |issue=3 |pages=320–324 |doi=10.1016/S0091-2182(99)00055-5|pmid=10380450 }}

Consuming evening primrose oil may cause headache or stomach upset, may increase the risk of complications during pregnancy, and may increase the risk of bleeding in people given prescription drugs as anticoagulants, such as warfarin.{{cite web |title=Evening primrose |url=https://www.drugs.com/mca/evening-primrose |publisher=Drugs.com |access-date=24 June 2020 |date=14 October 2019}}

A number of perennial members of the genus are commonly cultivated and used in landscaping in the southwestern United States. Popular species include tufted evening primrose (Oenothera caespitosa), Mexican evening primrose (Oenothera berlanderii), and Saltillo evening primrose (Oenothera stubbei).Jones W. and C. Sacamano. Landscape Plants for Dry Regions. Fisher Books. 2000. {{ISBN|1-55561-190-7}}

Annual evening primroses are also popular ornamental plants in gardens. Many are fairly drought-resistant.

The first plants to arrive in Europe reached Padua from Virginia in 1614 and were described by the English botanist John Goodyer in 1621. Some species are now also naturalized in parts of Europe and Asia, and can be grown as far north as 65°N in Finland. The UK National Council for the Conservation of Plants and Gardens, based at Wisley, maintains an Oenothera collection as part of its National Collections scheme.

File:Oenothera macrocarpa a1.JPG|Oenothera macrocarpa

File:Oenothera rosea.JPG|Oenothera rosea

File:Oenothera caespitosa var marginata 4.jpg|Oenothera caespitosa var. marginata

File:Starr 051004-4684 Oenothera stricta subsp. stricta.jpg|Oenothera stricta ssp. stricta

File:Primrose-brighter.jpg|Oenothera sp. opening

File:Oclelandii.jpg|Oenothera clelandii

File:Oenothera drummondii2.jpg|Oenothera drummondii

File:Oenothera odorata 2.jpg|Oenothera odorata

File:Bloem van een Oenothera stricta 'Sulphurea'. 30-05-2024 (d.j.b.).jpg| Closed flower.

{{Reflist|2}}

{{Commonscat|Oenothera|Oenothera}}

{{Wikispecies|Oenothera|Oenothera}}

• [http://botany.si.edu/onagraceae/ Onagraceae - The Evening Primrose Family.] Smithsonian National Museum of Natural History.
• [http://www.pfaf.org/database/plants.php?Oenothera+biennis Plants For A Future]
• {{cite journal|last1=Szewczyk|first1=Karolina|last2=Lewandowska|first2=Urszula|last3=Owczarek|first3=Katarzyna|title=Influence of Polyphenol Extract from Evening Primrose (Oenothera Paradoxa) Seeds on Proliferation of Caco-2 Cells and on Expression, Synthesis and Activity of Matrix Metalloproteinases and Their Inhibitors|journal=Polish Journal of Food and Nutrition Sciences|date=2014|volume=64|issue=3|pages=181–191|doi=10.2478/pjfns-2013-0003|doi-access=free|hdl=11652/1078|hdl-access=free}}

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Category:Onagraceae genera

Category:Night-blooming plants

Category:Medicinal plants