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peanuts
Peanut (Arachis hypogaea)

Peanut ( Arachis hypogaea )

Systematics
Eurosiden I
Order : Fabales (Fabales)
Family : Legumes (Fabaceae)
Subfamily : Butterflies (Faboideae)
Tribe : Dalbergieae
Genre : peanuts
Scientific name
Arachis
L.

The Peanuts ( Arachis ) are a genus in the subfamily of the Pea family (Faboideae) within the family of legumes (Fabaceae). The 80 or so species are only found in the Neotropics . In addition to the globally used peanut ( Arachis hypogaea ), few other species are grown.

description

Illustration of peanut ( Arachis hypogaea )
Flower of Arachis glabrata

Appearance and leaves

The Arachis species grow as annual to perennial herbaceous plants . The stem is independently upright to creeping.

The alternate leaves are arranged in a petiole and a leaf blade. The pairs feathery leaf blade has at most two pairs rachis against constantly opposing almost seated pinna leaflet . The large, membranous stipules are partially fused with the petiole, there are no stipules of the leaflets.

Generative characteristics

The lateral, spiky inflorescences can contain two to seven flowers, but they are usually reduced to one flower. The bracts are membranous, the lowest having two tips.

The more or less sessile, hermaphrodite flowers are zygomorphic and five-fold with a double flower envelope . Of the five membranous, narrow sepals four are fused and the fifth is free; they enlarge to the point of fruit formation. The crown has the typical structure of the butterflies . The five petals are yellow, sometimes with red stripes. The flag is almost circular and only briefly nailed to the base. The two free wings are elongated and eyed. The shuttle is beaked and curved inwards. Often one or two of the original ten stamens are missing. All stamens have grown together. There are two forms of anthers, long and short alternate. The single almost sitting carpel usually has two or three, rarely up to six ovules . The base of the carpel, called the “gynophor”, elongates and curves after fertilization - this is how the fruit gets underground. The quickly ephemeral, very long, thin stylus ends in a tiny scar.

The famous legume of the peanut ( Arachis hypogaea )

The elongated legumes contain one to five, rarely up to six seeds and are somewhat constricted between them. These underground legumes do not open on their own. The thick fruit walls have a net-like surface. The oval or elongated seed has two abundant oleaginous seed leaves ( cotyledons ).

In Arachis , the number of chromosomes in the diploid species is 2n = 20 and the tetraploid species 2n = 40.

distribution

The original range of the approximately 80 species is mainly in eastern to central South America , but extends south to Paraguay and Uruguay.

Section Arachis : The peanut ( Arachis hypogaea ), illustration from Francisco Manuel Blanco: Flora de Filipinas
Caulorrhizae section : habit, leaves and flowers of Arachis pintoi
Caulorrhizae section : Arachis pintoi
Rhizomatosae section : Arachis glabrata

Systematics

The genus name Arachis was first published in 1753 by Carl von Linné with the type species Arachis hypogaea L. in Species Plantarum , 2, p. 741. Krapovickas & Gregory 1994 lists 69 species and Valls & Simpson 2005 11 species were added. The genus Arachis belongs to the tribe Dalbergieae in the subfamily of the Faboideae within the family of the Fabaceae .

The genus Arachis is divided into nine sections with around 80 species:

use

Peanuts as a snack

In addition to the well-known peanut species ( Arachis hypogaea ), a few other species are also grown, for example Arachis pintoi , Arachis glabrata and Arachis sylvestris . Several species are involved in the cultivated forms of the peanut ( Arachis hypogaea ). Edible oil and peanut butter are produced from the seeds and components are now found in many products in the food industry. The seeds ("peanut kernels") are eaten roasted.

Arachis repens leaves

Arachis repens is also used as an ornamental plant.

health

Because of the fiber they contain, peanuts are good for digestion .

swell

  • Ren Sa, Alfonso Delgado Salinas: Arachis , p. 132 - the same text online as the printed work , In: Wu Zheng-yi, Peter H. Raven & Deyuan Hong (eds.): Flora of China , Volume 10 - Fabaceae , Science Press and Missouri Botanical Garden Press, Beijing and St. Louis, 2010, ISBN 978-1-930723-91-7 .
  • SI Ali: Papilionaceae in the Flora of Pakistan : Arachis - online .
  • RK Brummitt, DK Harder, GP Lewis et al .: Arachis in Leguminosae , Flora Zambesiaca , Volume 3, Part 3, 2000: online .
  • Robert Hegnauer : Chemotaxonomie der Pflanzen , Volume XIb-2, Springer, 2001, ISBN 3-7643-5862-9 , ( Arachis : from page 503).
  • Ravi Koppolu, Hari D. Upadhyaya, Sangam L. Dwivedi et al .: Genetic relationships among seven sections of genus Arachis studied by using SSR markers. In: BMC Plant Biology. 2010, Volume 10, Article 15, doi : 10.1186 / 1471-2229-10-15 .
  • A. Krapovickas, WC Gregory: Taxonomía del género Arachis (Leguminosae). In: Bonplandia. 8, 1994, pp. 1-186.
  • JFM Valls, CE Simpson: New species of Arachis from Brazil, Paraguay, and Bolivia. In: Bonplandia. Volume 14, 2005, pp. 35-64.
  • Guillermo Seijo, Graciela I. Lavia, Aveliano Fernandez et al .: Genomic relationships between the cultivated peanut (Arachis hypogaea, Leguminosae) and its close relatives revealed by double GISH. In: American Journal of Botany. Volume 94, Issue 12, 2007, pp. 1963–1971, doi : 10.3732 / ajb.94.12.1963 .
  • Marcos A. Gimenes, Catalina R. Lopes, Jose FM Valls: Genetic relationships among Arachis species based on AFLP. In: Genetics and Molecular Biology , Volume 25, No. 3, São Paulo, 2002. doi : 10.1590 / S1415-47572002000300017 .

Individual evidence

  1. ↑ First publication scanned at biodiversitylibrary.org.
  2. ^ A b Arachis in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland.
  3. ↑ Arachis entry at ILDIS = International Legume Database & Information Service .
  4. ↑ Data sheet Arachis pintoi ( Memento of the original from February 4, 2010 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. at Tropical Forages . @1@ 2Template: Webachiv / IABot / www.tropicalforages.info

Web links

Commons : Peanuts  - Collection of images, videos, and audio files