Articles on this page are available in 1 other language: Dutch (1) (learn more)

Overview

Brief Summary

On sunny days, you rarely see evening primrose flowers blossoming. As evening sets in, the petals open up within a minute, blossoming only one night long. The flowers emit a strong peculier odor to attract night insects. If the following day is cloudy they will blossom longer. The petals reflect ultra violet light, except at the foot. Because insects can detect ultra violet light, they see a dark heart surrounded by a light halo and are directed to the nectar. There are three species of evening primrose, which closely resemble one another.
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© Copyright Ecomare

Source: Ecomare

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Comprehensive Description

Description

Annual, biennial or perennial herbs. Stipules 0. Leaves alternate, entire to pinnatifid. Flowers in axils of often reduced leaves. Bracteoles 0. Hypanthium present. Sepals 4. Petals 4, yellow, white or purplish-rose. Stamens 8. Stigma deeply 4-lobed. Seeds glabrous.Evening primroses, so called because they often flower in the evening.
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© Mark Hyde, Bart Wursten and Petra Ballings

Source: Flora of Zimbabwe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Distribution

Localities documented in Tropicos sources

Oenothera L.:
Brazil (South America)
Honduras (Mesoamerica)
United States (North America)
Colombia (South America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO 63110 USA

Source: Missouri Botanical Garden

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Ecology

Habitat

Depth range based on 6 specimens in 1 taxon.

Environmental ranges
  Depth range (m): 0.5 - 0.5
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Associations

Foodplant / open feeder
imago of Altica oleracea grazes on leaf of Oenothera
Other: sole host/prey

Foodplant / pathogen
Ditylenchus dipsaci infects and damages live, reduced leaf (upper) of Oenothera

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Molecular Biology and Genetics

Molecular Biology

Statistics of barcoding coverage

Barcode of Life Data Systems (BOLD) Stats
                                        
Specimen Records:74Public Records:16
Specimens with Sequences:55Public Species:9
Specimens with Barcodes:52Public BINs:0
Species:22         
Species With Barcodes:18         
          
Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Barcode data

Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Locations of barcode samples

Collection Sites: world map showing specimen collection locations for Oenothera

Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Wikipedia

Oenothera

Oenothera is a genus of about 145[3] species of herbaceous flowering plants native to the Americas.[4] It is the type genus of the family Onagraceae. Common names include evening primrose, suncups, and sundrops. They are not closely related to the true primroses (genus Primula).

Description[edit]

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.[5] One of the most distinctive features of the flower is the stigma, which has four branches in an X shape.[6]

Ecology[edit]

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. 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, evening primroses 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 outcompeted by other species.

Origin[edit]

The genus Oenothera may have originated in Mexico and Central America,[7][8] 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.[4] 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.[8][9] 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.[7][10]

This 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.[11] 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.[12][13]

Taxonomy[edit]

Evening primroses were originally assigned to the genus Onagra, which gave the family Onagraceae its name. Onagra (meaning "(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 is believed to be derived from the Greek words ονος θηρας (onos theras), meaning "donkey catcher", or οινος θηρας (oinos theras), meaning "wine seeker".[14] In addition, the Latin oenothera means "a plant whose juices may cause sleep".[15]

In 1905, while studying the genetics of Oenothera lamarckiana, Hugo de Vries discovered a variant with a chromosome number of 2n = 28 compared with 2n = 14 for O. lamarckiana. DeVries was unable to breed this variant with O. lamarckiana. He named the variant Oenothera gigas.[16]

Uses[edit]

Certain Oenothera plants have edible parts. The roots of O. biennis are reportedly edible in young plants.[17]

Evening primrose oil is sometimes marketed as a cancer remedy, but according to the American Cancer Society there is very little evidence for its effectiveness, and "neither GLA nor other GLA-rich supplements (such as evening primrose oil) have been convincingly shown to be useful in preventing or treating any other health conditions."[18] A Cochrane meta-analysis published in April, 2013, found evening primrose oil and borage oil to be ineffective for eczema.[19]

Cultivation[edit]

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).[20]

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.

Gallery[edit]

References[edit]

  1. ^ "Genus: Oenothera L". Germplasm Resources Information Network. United States Department of Agriculture. 2004-03-22. Retrieved 2010-10-28. 
  2. ^ "GRIN Species Records of Oenothera". Taxonomy for Plants. USDA, ARS, National Genetic Resources Program. Retrieved July 11, 2010. 
  3. ^ Singh, S., et al. (2012). An updated review on the Oenothera genus. J. Chin. Integr. Med 10, 717-25.
  4. ^ a b Mihulka, S. and P. Pyšek. (2001). Invasion history of Oenothera congeners in Europe: a comparative study of spreading rates in the last 200 years. Journal of Biogeography 28(5), 597-609.
  5. ^ Gumbo Lily (Oenothera caespitosa). Native Wildflowers of the North Dakota Grasslands. USGS Northern Prairie Wildlife Research Center.
  6. ^ Peterson, R. T. and M. McKenny (1968). A Field Guide to Wildflowers of Northeastern and North-central North America. Boston: Houghton Mifflin. ISBN 0-395-91172-9. 
  7. ^ a b Raven, P. H., et al. (1979). "An outline of the systematics of Oenothera subsect. Euoenothera (Onagraceae)". Systematic Botany (Systematic Botany, Vol. 4, No. 3) 4 (3): 242–252. doi:10.2307/2418422. JSTOR 2418422. 
  8. ^ a b Dietrich, W., et al. (1997). Systematics of Oenothera section Oenothera subsection Oenothera (Onagraceae). Laramie: The American Society of Plant Taxonomists. ISBN 0-912861-50-9. 
  9. ^ Cleland, R. E. (1972). Oenothera - Cytogenetics and evolution. Boston: Academic Press. ISBN 0-12-176450-8. 
  10. ^ Rostanski, K. (1985). "The classification of subsection Oenothera (section Oenothera, Oenothera L., Onagraceae)". Feddes Report 96 (1–2): 3–14. 
  11. ^ Rauwolf, U., et al. (2008). "Molecular marker systems for Oenothera genetics". Genetics 180 (3): 1289–1306. doi:10.1534/genetics.108.091249. PMC 2581935. PMID 18791241. 
  12. ^ Cleland, R. E. (1972). Oenothera - Cytogenetics and Evolution. Boston: Academic Press. ISBN 0-12-176450-8. 
  13. ^ Harte, C. (1994). Oenothera - Contributions of a Plant to Biology. Berlin: Springer-Verlag. ISBN 3-540-53114-9. 
  14. ^ Gledhill, D. (2008). The Names of Plants (4 ed.). Cambridge University Press. p. 278. ISBN 978-0-521-86645-3. 
  15. ^ Quattrocchi, U. (2000). CRC World Dictionary of Plant Names. III: M-Q. CRC Press. p. 1860. ISBN 978-0-8493-2677-6. 
  16. ^ "Observed Instances of Speciation". Joseph Boxhorn. 1995-09-01. 
  17. ^ Oenothera biennis. Ohio Perennial and Biennial Weed Guide. The Ohio State University Extension.
  18. ^ "Gamma Linolenic Acid". American Cancer Society. 13 May 2010. Retrieved August 2013. 
  19. ^ Bamford, J. T., et al. (2013). Oral evening primrose oil and borage oil for eczema. Cochrane Database of Systematic Reviews 4, CD004416.
  20. ^ Jones W. and C. Sacamano. Landscape Plants for Dry Regions. Fisher Books. 2000. ISBN 1-55561-190-7
Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

Source: Wikipedia

Unreviewed

Article rating from 0 people

Average rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!