Amaranthus palmeri
Encyclopedia
Amaranthus palmeri is a species of edible flowering plant
in the amaranth
genus. It has several common names, including Palmer's amaranth, Palmer amaranth, Palmer's pigweed, and carelessweed. It is native to most of the southern half of North America. Populations in the eastern United States are probably naturalized
. It has also been introduced to Europe, Australia, and other areas. The plant is fast-growing and highly competitive.
s, are edible and highly nutritious. Palmer amaranth was once widely cultivated and eaten by Native Americans across North America, both for its abundant seeds and as a cooked or dried green vegetable. Other related amaranthus species have been grown as crops for their greens and seeds for thousands of years in Mexico, South America, the Caribbean, Africa, India, and China.
The plant is however toxic to livestock animals, due to the presence of nitrates in the leaves. Palmer amaranth has a tendency to absorb excess soil nitrogen
, and if grown in overly fertilized soils, it can therefore contain excessive levels of nitrates, even for humans. Like spinach and many other leafy greens, amaranth leaves also contain oxalic acid
, which can be harmful to individuals with kidney problems if consumed in excess.
Because of its toxicity to livestock
, and scarce familiarity in the United States with the uses of amaranths as food, Palmer amaranth is rarely consumed nowadays, despite its ubiquity and resistance to drought. Unlike the grain and leaf amaranths of other regions, it has not been cultivated or further improved by recent agricultural breeding
. As a result, the primary economic importance of Palmer amaranth to American farmers has been as a noxious weed and a competitor to more marketable crops, rather than as a crop in its own right.
and soybean
crops in the southern United States because in many places, the plant has developed resistance
to glyphosate, the active ingredient in the widely-used broadleaf herbicide
Roundup.
Glyphosate resistant pigweed not only dominates in cotton fields, it has wide ranging effects on other crops and productions as well. In the fall of 2005, North Carolina researchers collected Palmer pigweed by seed from 280 fields from the Virginia border to the South Carolina border. However, in 2001 Palmer amaranthus was found in the southern quarter of Illinois and appeared to be moving to northern Illinois in 2006.
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
in the amaranth
Amaranth
Amaranthus, collectively known as amaranth, is a cosmopolitan genus of herbs. Approximately 60 species are recognized, with inflorescences and foliage ranging from purple and red to gold...
genus. It has several common names, including Palmer's amaranth, Palmer amaranth, Palmer's pigweed, and carelessweed. It is native to most of the southern half of North America. Populations in the eastern United States are probably naturalized
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
. It has also been introduced to Europe, Australia, and other areas. The plant is fast-growing and highly competitive.
Uses
The leaves, stems and seeds of Palmer amaranth, like those of other amaranthAmaranth
Amaranthus, collectively known as amaranth, is a cosmopolitan genus of herbs. Approximately 60 species are recognized, with inflorescences and foliage ranging from purple and red to gold...
s, are edible and highly nutritious. Palmer amaranth was once widely cultivated and eaten by Native Americans across North America, both for its abundant seeds and as a cooked or dried green vegetable. Other related amaranthus species have been grown as crops for their greens and seeds for thousands of years in Mexico, South America, the Caribbean, Africa, India, and China.
The plant is however toxic to livestock animals, due to the presence of nitrates in the leaves. Palmer amaranth has a tendency to absorb excess soil nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
, and if grown in overly fertilized soils, it can therefore contain excessive levels of nitrates, even for humans. Like spinach and many other leafy greens, amaranth leaves also contain oxalic acid
Oxalic acid
Oxalic acid is an organic compound with the formula H2C2O4. This colourless solid is a dicarboxylic acid. In terms of acid strength, it is about 3,000 times stronger than acetic acid. Oxalic acid is a reducing agent and its conjugate base, known as oxalate , is a chelating agent for metal cations...
, which can be harmful to individuals with kidney problems if consumed in excess.
Because of its toxicity to livestock
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
, and scarce familiarity in the United States with the uses of amaranths as food, Palmer amaranth is rarely consumed nowadays, despite its ubiquity and resistance to drought. Unlike the grain and leaf amaranths of other regions, it has not been cultivated or further improved by recent agricultural breeding
Plant breeding
Plant breeding is the art and science of changing the genetics of plants in order to produce desired characteristics. Plant breeding can be accomplished through many different techniques ranging from simply selecting plants with desirable characteristics for propagation, to more complex molecular...
. As a result, the primary economic importance of Palmer amaranth to American farmers has been as a noxious weed and a competitor to more marketable crops, rather than as a crop in its own right.
As a weed
Palmer amaranth is considered a threat most specifically to the production of genetically modified cottonCotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
and soybean
Soybean
The soybean or soya bean is a species of legume native to East Asia, widely grown for its edible bean which has numerous uses...
crops in the southern United States because in many places, the plant has developed resistance
Pesticide resistance
Pesticide resistance is the adaptation of pest population targeted by a pesticide resulting in decreased susceptibility to that chemical. In other words, pests develop a resistance to a chemical through natural selection: the most resistant organisms are the ones to survive and pass on their...
to glyphosate, the active ingredient in the widely-used broadleaf herbicide
Herbicide
Herbicides, also commonly known as weedkillers, are pesticides used to kill unwanted plants. Selective herbicides kill specific targets while leaving the desired crop relatively unharmed. Some of these act by interfering with the growth of the weed and are often synthetic "imitations" of plant...
Roundup.
Glyphosate resistant pigweed not only dominates in cotton fields, it has wide ranging effects on other crops and productions as well. In the fall of 2005, North Carolina researchers collected Palmer pigweed by seed from 280 fields from the Virginia border to the South Carolina border. However, in 2001 Palmer amaranthus was found in the southern quarter of Illinois and appeared to be moving to northern Illinois in 2006.