''Amaranthus retroflexus'' is a species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

in the family

Amaranthaceae Amaranthaceae is a family of flowering plants commonly known as the amaranth family, in reference to its type genus ''Amaranthus''. It includes the former goosefoot family Chenopodiaceae and contains about 165 genera and 2,040 species, making it ...

with several

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...

s, including red-root amaranth, redroot pigweed, red-rooted pigweed, common amaranth, pigweed amaranth, and common tumbleweed. page 470

Description

''Amaranthus retroflexus,'' true to one of its common names, forms a

tumbleweed A tumbleweed is a structural part of the above-ground anatomy of a number of species of plants. It is a diaspore that, once mature and dry, detaches from its root or stem and rolls due to the force of the wind. In most such species, the tumble ...

. It is native to the tropical Americas, but is widespread as an

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...

on most continents in a great number of habitats. This is an erect, annual herb reaching a maximum height near . The leaves are nearly long on large individuals, the ones higher on the stem having a lance shape and those lower on the plant diamond or oval in shape. The plant is

monoecious Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system alongside gynomonoecy, andromonoecy and trimonoecy. Monoecy is conne ...

, with individuals bearing both male and female flowers. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

is a large, dense cluster of flowers interspersed with spiny green

bract In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...

s. The fruit is a capsule less than long with a "lid" which opens to reveal a tiny black seed. Another of ''A. retroflexus's'' common names is "pigweed" because it grows where hogs are pasture-fed.

Culinary use

This plant is eaten as a vegetable in different places of the world. No species of genus ''Amaranthus'' is known to be poisonous, but the leaves contain

oxalic acid Oxalic acid is an organic acid with the systematic name ethanedioic acid and formula . It is the simplest dicarboxylic acid. It is a white crystalline solid that forms a colorless solution in water. Its name comes from the fact that early inve ...

and may contain

nitrate Nitrate is a polyatomic ion A polyatomic ion, also known as a molecular ion, is a covalent bonded set of two or more atoms, or of a metal complex, that can be considered to behave as a single unit and that has a net charge that is not zer ...

s if grown in nitrate-rich soils, so the water should be discarded after boiling. The young shoots and leaves can be eaten raw. The leaves are high in calcium, iron, protein, and

phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ear ...

. ''A. retroflexus'' was used for a multitude of food and medicinal purposes by many Native American groups in the US West. It is among the species consumed as a vegetable in Mexican markets as ''Quelite quintonil''. It is used in the

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

n state of

Kerala Kerala ( ; ) is a state on the Malabar Coast of India. It was formed on 1 November 1956, following the passage of the States Reorganisation Act, by combining Malayalam-speaking regions of the erstwhile regions of Cochin, Malabar, South ...

to prepare a popular dish known as ''

thoran Thoran ( ml, തോരൻ, pronounced ; or upperi in Northern Kerala is a class of dry vegetable dishes combined with coconut that originated in the Indian state of Kerala. This common dish is usually eaten with rice and curry and is also par ...

'' by combining the finely cut leaves with grated

coconut The coconut tree (''Cocos nucifera'') is a member of the palm tree family ( Arecaceae) and the only living species of the genus ''Cocos''. The term "coconut" (or the archaic "cocoanut") can refer to the whole coconut palm, the seed, or the ...

chili pepper Chili peppers (also chile, chile pepper, chilli pepper, or chilli), from Nahuatl '' chīlli'' (), are varieties of the berry-fruit of plants from the genus ''Capsicum'', which are members of the nightshade family Solanaceae, cultivated for ...

garlic Garlic (''Allium sativum'') is a species of bulbous flowering plant in the genus ''Allium''. Its close relatives include the onion, shallot, leek, chive, Allium fistulosum, Welsh onion and Allium chinense, Chinese onion. It is native to South A ...

turmeric Turmeric () is a flowering plant, ''Curcuma longa'' (), of the ginger family, Zingiberaceae, the rhizomes of which are used in cooking. The plant is a perennial, rhizomatous, herbaceous plant native to the Indian subcontinent and Southeast Asi ...

and other ingredients. The seeds are edible raw or toasted, and can be ground into flour and used for bread, hot cereal, or as a thickener.

Use as fodder

Like many other species of ''Amaranthus'', this plant may be harmful and even deadly when fed to

cattle Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult mal ...

and

pig The pig (''Sus domesticus''), often called swine, hog, or domestic pig when distinguishing from other members of the genus '' Sus'', is an omnivorous, domesticated, even-toed, hoofed mammal. It is variously considered a subspecies of ''Sus ...

s in large amounts over several days. Such forage may cause fatal

nephrotoxicity Nephrotoxicity is toxicity in the kidneys. It is a poisonous effect of some substances, both toxic chemicals and medications, on kidney function. There are various forms, and some drugs may affect kidney function in more than one way. Nephrotoxin ...

,FEIS Ecology
/ref> presumably because of its high oxalate content. Other symptoms, such as bloat or methylglobineamia in the most severe cases, might reflect its high nitrate content. However, when supplied in moderation, it is regarded as an exceptionally nutritious fodder.Watt, John Mitchell; Breyer-Brandwijk, Maria Gerdina: The Medicinal and Poisonous Plants of Southern and Eastern Africa 2nd ed Pub. E & S Livingstone 1962

As a weed

''A. retroflexus'' is a

weed A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...

and has developed resistance against

fomesafen Fomesafen is the ISO common name for an organic compound used as an herbicide. It acts by inhibiting the enzyme protoporphyrinogen oxidase which is necessary for chlorophyll synthesis. Soybeans naturally have a high tolerance to fomesafen, via ...

Northeast China Northeast China or Northeastern China () is a geographical region of China, which is often referred to as "Manchuria" or "Inner Manchuria" by surrounding countries and the West. It usually corresponds specifically to the three provinces east of t ...

References

External links

*
Jepson Manual Treatment
*
Amaranthus retroflexus L.
Medicinal Plant Images Database (School of Chinese Medicine, Hong Kong Baptist University) * {{Taxonbar, from=Q157663 retroflexus Flora of North America Flora of South America Plants described in 1753 Taxa named by Carl Linnaeus Kerala cuisine Plants used in Native American cuisine Invasive plant species in Japan