Amaranthus palmeri

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Amaranthus palmeri
Amaranthus palmeri

Amaranthus palmeri

Systematics
Order : Clove-like (Caryophyllales)
Family : Foxtail family (Amaranthaceae)
Subfamily : Amaranthoideae
Genre : Amaranth ( Amaranthus )
Subgenus : Acnida
Type : Amaranthus palmeri
Scientific name
Amaranthus palmeri
S. Watson
Nathaniel Lord Britton, Addison Brown: An Illustrated Flora of the Northern United States, Canada and the British Possessions , 2nd edition, 1913.

Amaranthus palmeri is a type of plant from the genus Amarant within the foxtail family(Amaranthaceae).

description

Amaranthus palmeri forms hybrids with a number of related species, some of which are quite common and, especially in hybrid flocks, are difficult to distinguish from the parent species after backcrossing . To distinguish between similar North American species that also grow as field weeds, cf.

Vegetative characteristics

Amaranthus palmeri grows as an upright, annual, herbaceous plant with ascending side shoots. The above-ground parts of the plant are bare. Stems and leaves are green in color, sometimes tinged with reddish or pink. It regularly reaches a height of about one, in exceptional cases two to three meters. The leaves are divided into a petiole and a leaf blade. The strikingly long petiole is about as long as the leaf blade. The leaf blade is rhombic to lanceolate. Only the tip of the leaf has fine hair as an extension of the midrib.

Generative characteristics

Amaranthus palmeri is dioeciously separated sexes ( diocesan ). The 20 to 30 centimeter long inflorescence is long and narrow and densely covered with flowers, making the branching pattern (a thyrse ) difficult to recognize. They sit terminally on the main shoot and on the leafy side shoots. If there are leafless flower stems, they are loosely arranged and each have a supporting leaf .

The unisexual flowers are five-fold. Male flowers have five stamens and five inconspicuous petals , the inner ones about 2.5 to 3 millimeters long and blunt to marginalized, the outermost 3.5 to 4 millimeters long and pointed with a protruding central rib. The female flowers have five petals of comparable length, curved back, with conspicuous branched veins, the four inner spatula-shaped with an edged tip, the outermost pointed with a central rib protruding as a small tip. They have two, rarely three styles .

When the fruit ripens, the fruit disintegrates into cup-shaped parts. The seeds are about a millimeter long or a little longer and red-brown in color.

Chromosome number

The number of chromosomes is 2n = 34.

ecology

In Amaranthus palmeri is a therophytes ; it is a summer annual plant . The main flowering period is from summer to autumn, but there are isolated flowering and fruiting specimens throughout the year. Amaranthus palmeri is one of the C4 plants .

Occurrence

Amaranthus palmeri is originally distributed in North America from the southwest of the United States to northern Mexico. From here, Amaranthus palmeri has spread strongly through human influence and displacement, especially in fields. From 1962 she performed in Arkansas, from 1963 in Nebraska, from 1966 in South Carolina, from 1967 also in Florida.

There are localities for the US states of Oklahoma , Texas , New Mexico , Nevada , Arizona and California and for the Mexican states of Baja California , Baja California Sur , Chihuahua , Coahuila , Durango , Nuevo León , Sinaloa , Sonora , Tamaulipas , Zacatecas , Colima , Guerrero , Jalisco , Mexico , Michoacán , Morelos , Oaxaca and Veracruz . Amaranthus palmeri is a neophyte in many areas of the world . Thus Amaranthus palmeri introduced as "weed" for example to Argentina.

In Europe, inconsistent introductions existed as adventitious plants near cotton mills since 1908, whereby initially only male plants were observed. Since around 2007, more and more plants of both sexes have been observed in Spain, which indicates the beginning of naturalization there.

Original habitats of Amaranthus palmeri are the open banks of year-round (perennial) or occasionally water-bearing (intermittent) flowing waters , in which it grows in silty, sandy to gravelly substrates . From these natural sites it has passed to man-made sites with similar site conditions; Initially the edges of ditches, railways and roads, later increasingly garden land and fields.

In the southern United States, Amaranthus palmeri is one of the most problematic arable weeds today . Although Amaranthus palmeri has been able to expand its area significantly to the north in the past few decades, it has so far been of less importance as a "weed", especially in northern latitudes with a colder climate, for example in Iowa . Their further spread is feared.

Taxonomy

The first description of Amaranthus palmeri was made in 1877 by Sereno Watson . Traditionally, the species is led with a number of similar, also dioecious species in a section Saueranthus in the subgenus Acnida , which was regarded by numerous older taxonomists as a separate genus. According to the phylogemical method (analysis of the relationship based on the comparison of homologous DNA sequences), there was unexpectedly a close relationship with monoecious species such as Amaranthus spinosus . Accordingly, the traditional subgenus Acnida would not be a monophyletic unit.

Agriculture

In 2006 it was first observed in Georgia that plant specimens of Amaranthus palmeri had developed resistance to glyphosate . In addition to resistance to the total herbicide glyphosate, there are also populations with resistance to most of the other common herbicides such as atrazine , diuron and other photosynthesis inhibitors, to herbicides of the active ingredient class of dinitroanilines , to imazaquin and other imidazolinones and which work on a similar principle (as acetolactate synthase Inhibitors) effective sulfonylureas . So far, however, there are none that would be resistant to all these substance classes at the same time. Herbicide resistance was experimentally transferred from Amaranthus palmeri to a related species ( Amaranthus rudis ) by crossing the species with each other in the experiment and backcrossing the resulting hybrid with the parent species. It is very likely that such phenomena will also occur in the field. Amaranthus palmeri is therefore increasingly becoming a problem in US agriculture. In particular, glyphosate-resistant plants in cotton and soybean cultivation pose a major problem: In these crops, the resistance to the herbicide has been transgenically transferred to the crop, which is what today's cultivation methods are based on, in that all plants except the resistant ones are based on the use of glyphosate Crop should be killed.

Seeds of Amaranthus palmeri , like some other Amaranthus species in North and South America, were collected as food by indigenous peoples such as the Mohave , Chemehuevi , Papago , Cocopa and Tarahumara in what is now northern Mexico and Arizona , but the species was probably not cultivated for agriculture .

Individual evidence

  1. ↑ a b c J. J. Wassom, PJ Tranel (2005): Amplified Fragment Length Polymorphism-Based Genetic Relationships Among Weedy Amaranthus Species. In: Journal of Heredity , 96, 4, pp. 410-416. doi : 10.1093 / jhered / esi065 (open access)
  2. ↑ Larry Steckel, 2005: Mature Pigweed Identification - University of Tennessee Extension PDF.
  3. ^ A b Donald B. Pratt, Micheal DK Owen, Lynn G. Clark, Anna Gardner, 1999: Identification of the weedy pigweeds and waterhemps of Iowa PDF.
  4. ↑ a b c d Sergio Morichetti, Jason Ferrell, Ramon Leon: Amaranthus palmeri Palmer Amaranth. US Department of Agriculture, UF / IFAS Extension Service, University of Florida, IFAS, Florida Publication # SS-AGR-336. on-line.
  5. ↑ a b c d e f Jonathan D. Sauer: Revision of the dioecious Amaranths. In: Madroño , Volume 13, 1, 1955, pp. 5-46. online at JSTOR
  6. ↑ Amaranthus palmeri at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
  7. ↑ a b Jonathan D. Sauer: The dioecious Amaranths: a new species name and major range extensions. In: Madroño , Volume 21, 6, 1972, pp. 426-434. online at JSTOR
  8. ↑ a b c Amaranthus palmeri in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved December 21, 2015.
  9. ↑ Sergio Morichetti, Juan José Cantero, César Núñez, Gloria E. Barboza, Luis Ariza Espinar, Andrea Amuchastegui, Jason Ferrell: Sobre la presencia de Amaranthus palmeri (Amaranthaceae) en Argentina. In: Boletín de la Sociedad Argentina de Botánica , Volume 48, 2, 2013, pp. 347–354.
  10. ↑ Filip Verloowe, Enrique Sánchez-Gullón: New records of interesting Xenophytes in the Iberian Peninsula. In: Acta Botanica Malacitana , Volume 33, 2008, pp. 147-167.
  11. ↑ Sergei L. Mosyakin & Kenneth R. Robertson (1996): New infrageneric taxa and combinations in Amaranthus (Amaranthaceae). Annales Botanici Fennici 33 (4): 275-281.
  12. ↑ AS Culpepper, TL Gray, WK Vencill, JM Kichler, TM Webster, SM Brown et al .: Glyphosate-resistant Palmer amaranth (Amaranthus palmeri) confirmed in Georgia. Weed Sci. Volume 54, 2006, pp. 620-626. doi : 10.1614 / WS-06-001R.1
  13. ↑ Denise K. Wetzel, Michael J. Horak, Daniel Z. Skinner, Peter A. Kulakow (1999): Transferal of Herbicide Resistance Traits from Amaranthus palmeri to Amaranthus rudis. Weed Science 47 (5): 538-543. online at JSTOR
  14. ↑ Julienne Isaacs: Palmer amaranth is a looming concern: This aggressive, herbicide resistance weed has been traveling north, and may be in our fields soon. Grain News , Volume 41, Issue 2, January 20, 2015.
  15. ↑ Stephen O. Duke & Stephen B. Powles (2010): Glyphosate-Resistant Crops and Weeds: Now and in the Future. AgBioForum 12 (3/4) Article 10 online

Web links

Commons : Amaranthus palmeri  - Collection of images, videos and audio files