Evening primrose

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Evening primrose
Common evening primrose (Oenothera biennis), illustration

Common evening primrose ( Oenothera biennis ), illustration

Systematics
Rosids
Eurosiden II
Order : Myrtle-like (Myrtales)
Family : Evening primrose family (Onagraceae)
Subfamily : Onagroideae
Genre : Evening primrose
Scientific name
Oenothera
L.

The evening primrose ( Oenothera ) are a genus of plants within the family of the evening primrose family (Onagraceae). The 120 to 200 species are native to temperate to tropical areas in the New World . Some species were introduced to Europe as ornamental plants as early as the 17th century . They became wild and since then have been part of the Central European flora as neophytes or newly developed species and forms. These arise mainly from a species-specific hybridization of special ring chromosomes .

description

Rosette-like habit before the inflorescence of Oenothera stricta subsp. stricta

Vegetative characteristics

Evening primrose species are annual, biennial and perennial herbaceous plants . Some species form rhizomes as permanent organs as well as runners and creeping shoots for local distribution. Many species form tap roots . The long, undivided leaves are arranged in a basal rosette or alternately and spirally distributed on the stem . The leaf margin is smooth to lobed. Stipules are missing.

Generative characteristics

Flower diagram from Oenothera

The flowers are individually in the leaf axils or in differently structured inflorescences . The hermaphroditic flowers are radial symmetry and four-fold with a double flower envelope (perianth). The four green to yellowish sepals often have a red or purple markings and are fused with tubes. The four free petals are white, yellow or pink to purple in color. There are two circles with four stamens each. The four carpels have become an under-earth, vierfächerigen ovary grown, many ovules contains. The scar is four-lobed.

Stalked or sessile capsule fruits with many seeds are formed.

The number of chromosomes was 2n = 14, 28, 42 and 56.

ecology

Oenothera glazioviana flower opening in real time

Most species are predominantly pollinated by insects. The nectar in the flower tubes below can only be reached by long-nosed insects, but nectar predators simply bite the tubes open. Representatives of the swarmers (butterflies) can be found particularly often on the flowers , which can hardly be disturbed by the nectar intake even when people observe them very closely.

Just opened evening primrose is visited by Falter

For example, the pigeon tail and the medium owl can be observed as they hover in front of the flowers. One species of hawkmoth bears the name evening primrose hawk because of its preference for the nectar of this plant genus .

The flowers open shortly after sunset within a few minutes in one flowing movement. The speed with which it blooms cannot be observed in any other plant found in Central Europe . The main flowering time of most species is in the summer months of July and August, plants that bloom late or after the start of frost can be found.

A flower that opens is usually still odorless. Only after about 20 minutes to half an hour does their scent become intensely sweet, so that people sometimes find it intrusive and almost smelly , but are then visited by the insects mentioned.

The evening primrose produces hundreds of seeds per flower panicle. The seed chambers open as soon as the plant has died. Even the vibrations caused by a light wind are enough to distribute the seeds.

The biennial evening primrose species do not bloom until the second year. In the first year a rosette of leaves forms, lying flat on the ground . In the second year the plant develops upwards and forms one or more flower stalks, of which the terminal one can reach a height of up to 2 meters.

As invasive, biennial perennials, evening primrose is often and often predominantly developed in ruderal societies that are in dry and sunny (warm) locations. Meadow communities or stony free locations are also settled. Without repeated disturbance of the soil, these two-year-old plants will be displaced by perennial plants after just a few years , so that the germination capacity of the seeds and the occurrence of suitable areas are important for permanent settlement.

Systematics and distribution

The generic name Oenothera was first published in 1753 by Carl von Linné in Species Plantarum , 1, p. 346. Synonyms for Oenothera L. are: Anogra Spach , Baumannia Spach , Blennoderma Spach , Calylophis Spach . Orth var. Calylophus Spach , Galpinsia Britton , Gaura L. , Gaurella Small , Gauridium Spach , Gauropsis C.Presl , Gauropsis (Torr & Frem. .) Cockerell , Hartmannia Spach , Kneiffia Spach , Lavauxia Spach , Megapterium Spach , Meriolix Raf. ex Endl. , Onagra Mill. , Onosuris Raf. , Onosurus G.Don orth. Var., Pachylophus Spach , Peniophyllum Pennell , Raimannia Rose , Salpingia (Torr. & A. Gray) Raim. , Schizocarya Spach , Stenosiphon Spach , Usoricum Lunell , Xylopleurum Spach ; some of them today have the rank of sections or subsections. The type species is Oenothera biennis L.

A special feature is that complex heterozygosity creates hybrids spontaneously or in culture that do not occur in the original home of the evening primrose. The newly created hybrids behave like independent populations and are therefore regarded as species .

They originally come from the temperate areas of North, Central and South America. The center of biodiversity is southwestern North America. Many species are now naturalized in many other countries.

Oenothera deltoides subsp. deltoides
Oenothera glazioviana
Oenothera speciosa

The genus Oenothera belongs to the tribe Onagreae in the subfamily Onagroideae in the family Onagraceae. The genus Oenothera is divided into 18 sections:

  • Section Anogra ( Spach ) Walp.
  • Section Calylophus (Spach) Torr. & A.Gray :
    • Subsection Calylophus
    • Subsection Salpingia (Torr. & A.Gray ) WLWagner & Hoch
  • Section Contortae W.L.Wagner
  • Section Eremia W.L.Wagner
  • Section Gaura (L.) WLWagner & Hoch :
    • Subsection Campogaura ( PHRaven & DPGreg.) WLWagner & Hoch
    • Subsection Gaura
    • Subsection Gauridium (Spach) WLWagner & Hoch
    • Subsection Schizocarya (Spach) WLWagner & Hoch
    • Subsection Stenosiphon (Spach) WLWagner & Hoch
    • Subsection Stipogaura (PHRaven & DPGreg.) WLWagner & Hoch
    • Subsection Xenogaura (PHRaven & DPGreg.) WLWagner & Hoch
    • Subsection Xerogaura (PHRaven & DPGreg.) WLWagner & Hoch
  • Section Gauropsis (Torrey & Frém. ) WLWagner
  • Section Hartmannia (Spach) WLWagner & Hoch
  • Section Kleinia
  • Section Kneiffia (Spach) Walp.
  • Section Lavauxia (Spach) Walp. :
    • Subsection Australis W.L.Wagner & W.Dietr.
    • Lavauxia subsection
  • Section Leucocoryne W.L.Wagner & Hoch
  • Section Megapterium (Spach) Walp.
  • Section Oenothera :
    • Subsection Candela (W.Dietr. & WLWagner) WLWagner & Hoch
    • Subsection Emersonia (Munz) W.Dietr., PHRaven & WLWagner
    • Subsection Munzia W.Dietr.
      • Series: Allochroa (Fischer & Meyer) W.Dietr.
      • Series Clelandia W.Dietr.
      • Renneria series (Fischer) W.Dietr.
    • Subsection Nutantigemma W.Dietr. & WLWagner
    • Subsection Oenothera
    • Subsection Raimannia ( Rose ) W.Dietr.
  • Section Pachylophus (Spach) WLWagner
  • Section Paradoxus W.L.Wagner
  • Section Peniophyllum
  • Section Ravenia W.L.Wagner
  • Section Xanthocoryne W.L.Wagner & Hoch

The 120 to 200 types of evening primrose include:

use

Use as food

The tap root of the evening primrose, also known as "ham root" or "ham herb" because of its pink color when cooked, can be harvested in the first year from October and eaten as a vegetable. The plant must not set any flowers, otherwise the roots will lignify. They are prepared like black salsify. In the past, the cultivation of evening primrose was very common because the starchy wild herb was used as a meat substitute. In spring the leaves can be picked for salads or prepared like spinach . The edible flowers are also used as a decoration for salads. As an edible plant, it is also known under the names Rapontika , Rapunzel celery or yellow Rapunzel . Many types of Oenothera were and are used in folk medicine . Pharmacological tests confirm different medical effects depending on the species.

Use as a medicinal plant

The evening primrose has long been known as a medicinal plant, especially among the indigenous people of North America : They used it to relieve skin rashes or gynecological problems . The seeds of the evening primrose contain polyunsaturated fatty acids , vitamin E , 60 to 80 percent linoleic acid and about 9 percent gamma-linolenic acid . Gamma-linolenic acid is closely related to arachidonic acid , which plays a central role in inflammatory processes.

The evening primrose oils are obtained by cold pressing the seeds. Approximately 10,000 seeds are required for one gram of oil. Evening primrose oil has proven itself especially for the treatment of inflammatory skin diseases such as neurodermatitis . Applied externally, it has anti-inflammatory and anti-itch effects. It is taken in the form of capsules to prevent hardening of the arteries , allergies , arthritis and intestinal diseases. A tea made from dried leaves helps with diarrhea, gastrointestinal and digestive problems .

After a meta-analysis of over 27 studies on the effectiveness of evening primrose oil, the Cochrane Collaboration 2013 came to the final assessment that both evening primrose oil and borage oil, which is also rich in gamma-linolenic acid, when taken orally, have no effect on eczema beyond a placebo effect.

Use in cosmetics

Due to their effects, evening primrose oils are also used as active ingredients and additives in cosmetic articles, especially in skin creams. The ingredients have a calming effect on skin sensitive to irritation and can therefore be used pharmaceutically, especially on dry, flaky and itchy skin.

swell

  • Jiarui Chen, Peter C. Hoch, Warren L. Wagner: Oenothera. In: Wu Zheng-yi, Peter H. Raven, Deyuan Hong (Eds.): Flora of China . tape 13 : Clusiaceae through Araliaceae . Science Press / Missouri Botanical Garden Press, Beijing / St. Louis 2007, ISBN 978-1-930723-59-7 , pp. 423 (English, online ). (Sections Description and Systematics)
  • Peter C. Hoch, Peter H. Raven: Oenothera. In: Peter C. Hoch (Ed.): Flora of Pakistan 139: Onagraceae. Islamabad 1981 (online). (Section description)
  • Warren L. Wagner, Peter C. Hoch, Peter H. Raven: Revised classification of the Onagraceae. In: Systematic Botany Monographs. Volume 83, 2007, pp. 138-192 ( PDF file ).

Individual evidence

  1. a b Georg Philippi, A. Kappus (collaborators): Oenothera. In: Oskar Sebald, Siegmund Seybold, Georg Philippi (eds.): The fern and flowering plants of Baden-Württemberg . tape 4 : Special part (Spermatophyta, subclass Rosidae): Haloragaceae to Apiaceae . Eugen Ulmer, Stuttgart (Hohenheim) 1992, ISBN 3-8001-3315-6 , pp. 36-41 .
  2. Krzysztof Rostański: Oenothera. In: Rolf Wisskirchen, Henning Haeupler: Standard list of fern and flowering plants in Germany. With chromosome atlas . Ed .: Federal Agency for Nature Conservation (=  The fern and flowering plants of Germany . Volume 1 ). Eugen Ulmer, Stuttgart (Hohenheim) 1998, ISBN 3-8001-3360-1 , p. 334-340 .
  3. a b Evening Primrose. In: Matthias Zimmermann, Oberursel, www.natur-lexikon.com. 2019, accessed November 8, 2019 .
  4. a b c d e f Ordinary evening primrose. In: Verena Schmidt, Burda Senator Verlag GmbH, Offenburg, mein-schoener-garten.de. 2019, accessed November 8, 2019 .
  5. a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae Oenothera in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program . National Germplasm Resources Laboratory, Beltsville, Maryland.
  6. Krzysztof Rostański: Oenothera. In: Henning Haeupler, Thomas Muer: picture atlas of fern and flowering plants in Germany . Ed .: Federal Agency for Nature Conservation (=  The fern and flowering plants of Germany . Volume 2 ). Eugen Ulmer, Stuttgart (Hohenheim) 2000, ISBN 3-8001-3364-4 , pp. 329-339 .
  7. a b c d e f g h Walter Erhardt, Erich Götz, Nils Bödeker, Siegmund Seybold: The great pikeperch. Encyclopedia of Plant Names. Volume 2. Eugen Ulmer, Stuttgart 2008. ISBN 978-3-8001-5406-7 .
  8. Krzysztof Rostański, Lenz Meierott: The genus Oenothera L. Franken - (new for Germany) with special recognition of Oenothera stucchii Soldano. In: Forum Geobotanicum. Volume 2, 2006, pp. 19-23, doi: 10.3264 / FG.2006.0310 .
  9. Sumitra Singh, Rupinder Kaur, Surendra Kr. Sharma: An updated review on the Oenothera genus. In: Journal of Chinese Integrative Medicine. Volume 10, 2012, pp. 717-725, doi: 10.3736 / jcim20120701 .
  10. Bamford, JTM et al .: Oral evening primrose oil and borage oil for eczema . In: The Cochrane Library . 2013. doi : 10.1002 / 14651858.CD004416.pub2 .
  11. ^ S. Krist, G. Buchbauer, C. Klausberger: Lexicon of vegetable fats and oils. Springer Verlag, Vienna 2008, ISBN 978-3-211-75606-5 , p. 302.

Web links

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