Amaranthus blitum
(livid amaranth)

Pictures

Picture	Title	Caption	Copyright
Title Shoot and inflorescence Caption A. blitum Copyright ©Chris Parker/Bristol, UK	Shoot and inflorescence	A. blitum	©Chris Parker/Bristol, UK

Identity

Preferred Scientific Name

• Amaranthus blitum L. (1753)

Preferred Common Name

• livid amaranth

Other Scientific Names

• Albersia blitum var. oleraceus (L.) Hooker fil. (1885)
• Albersia oleracea (L.) Boiss. (1879)
• Albresia blitum ( L.) Kunth (1838)
• Amaranthus ascendens Loisel. (1810)
• Amaranthus ascendens Loisel. var. oleraceus (L.) Thell. ex Priszter (1953)
• Amaranthus ascendens Loisel. var. polygonoides (Moq.) Thell. (1912)
• Amaranthus ascendens subsp. polygonoides (Moq.) Thell. ex Pr. (1953)
• Amaranthus blitum L. subsp. emarginatus (Moq. ex Uline & Bray) Carretero, Muñoz Garm. y Pedrol
• Amaranthus blitum L. subsp. oleraceus (L.) Costea (2001)
• Amaranthus blitum subsp. polygonoides (Moq.) Carretero (1985)
• Amaranthus blitum var. ascendens (Loisel.) DC (1813)
• Amaranthus emarginatus Moq. ex Uline & Bray (1984)
• Amaranthus emarginatus Salzm. ex Moq. (1849) nom. illeg.
• Amaranthus lividus Hook. f. (1885) nom. illeg.
• Amaranthus lividus L. (1753)
• Amaranthus lividus L. proles oleraceus (L.) Thell. (1914)
• Amaranthus lividus L. proles polygonoides (Moq.) Thell. (1914)
• Amaranthus lividus L. subsp. polygonoides (Moq.) Thell. ex Probst (1949)
• Amaranthus lividus L. var. polygonoides (Moq.) Thell. ex Druce (1920)
• Amaranthus lividus proles ascendens (Loisel.) Thell. (1914)
• Amaranthus lividus proles lividus (Loisel.) Thell. (1914)
• Amaranthus lividus subsp. ascendens (Loisel.) Heukels (1934)
• Amaranthus lividus subsp. oleraceus (L.) Soó (1964)
• Amaranthus oleraceus L. (1763)
• Amaranthus polygonoides Zoll. (1845) nom. illeg.
• Blitum oleraceum (L.) Moench (1794)
• Euxolus ascendens (Loisel.) H. Hara (1938)
• Euxolus blitum (L.) Gren. (1869)
• Euxolus lividus (L.) Moq.,
• Euxolus oleraceus (L.) Moq. (1849)
• Euxolus viridis (L.) Moq. var. ascendens (Loisel.) Moq. (1849)
• Euxolus viridis L. var. polygonoides Moq. (1849)
• Glomeraria livida (L.) Cav. (1803)
• Glomeraria oleracea (L.) Cav. (1803)
• Pixydium oleraceum (L.) Moench (1794)
• Pyxidium lividum (L.) Moench (1794)

International Common Names

• English: pigweed
• Spanish: amaranto ascendente; bledo rojo
• French: amarante livide
• Portuguese: caruru-folha-de-cuia

Local Common Names

• Germany: Amarant (Bleifarbiger); Aufsteigender Amarant; Gruenlicher Amarant; Gruenlicher Fuchsschwanz
• Italy: amaranto livido
• Japan: inubiyu
• Netherlands: kleine majer
• Sweden: maallamarant
• USA: livid amaranth

EPPO code

• AMALI (Amaranthus lividus)

Summary of Invasiveness

A. blitum is a monoecious annual weed with a near global distribution. It grows between 10 and 80 cm tall, sometimes reaching 90 cm.

It was listed by Holm et al. (1979) as a serious or principal weed in ten countries, mainly across Europe and Asia but also including Nigeria and Mozambique. It occurs in a wide range of field and horticultural crops, grassland, orchards, plantations and vineyards. It appears to be especially troublesome in Japan, where it is one of the three main weeds of warmer upland farms (Takabayashi and Nakayama, 1981), and in the USA. In Minais Gerais province, Brazil, it is among the five most common weeds of coffee (Laca-Buendia and Brandao, 1994). A. blitum subsp. emarginatus potentially impacts on the native riparian herbaceous vegetation in Europe (Walter and Dobes, 2004).

Taxonomic Tree

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Dicotyledonae
•                     Order: Caryophyllales
•                         Family: Amaranthaceae
•                             Genus: Amaranthus
•                                 Species: Amaranthus blitum

Notes on Taxonomy and Nomenclature

The nomenclature of A. blitum is somewhat confused, with several Linnean names involved, and needs further molecular and biogeographical study to resolve the taxonomic issues. The names A. blitum and A. lividus L. were both described by Linnaeus (1753), but their use has changed over time, revealing disagreement amongst authors. Townsend (1985, 1988) and Aellen and Akeroyd (1993) used the name A. lividus, but the Committee for Spermatophyta, meeting in 1984 (Taxon, 1984), decided that a choice between the two earliest Linnaean names (A. blitum and A. lividus) should depend on the name selected when they were first combined. As it was Hooker who first combined the two taxa and selected the name A. blitum in 1885, this became the officially preferred name (John Wiersema, USDA, personal communication, 1998). Filias et al. (1980), writing in favour of the use of A. blitum, discussed the issue in detail.

Several infraspecific names of A. blitum have been published, owing to its high phenotypic variability. Townsend (1985, 1988) recognized two subspecies: lividus and polygonoides, on the basis of their somewhat different distributions, the former robust and generally erect, apparently originating in South America and the latter, smaller and generally prostrate, in Europe and Asia. Moquin-Tandon (1849) recognized five varieties (α-ε), three of which (α, δ, ε) now referred to A. graecizans L. Thellung (1914 sub. A. lividus) recognized four subtaxa (named ‘proles’).

Recent comprehensive lists of regional floras have treated differently the varibility of A. blitum, sometimes without recognizing  infraspecific taxa (e.g. Mosyakin and Robertson (2003), in the Flora of North America, or Akeroyd (1993) in Flora Europaea).

Recent detailed morphological investigations (e.g. Costea et al., 2001; Walter and Dobes, 2004) and ongoing studies (Iamonico, in prep.) show that there are three separate taxa that can be distinguished by features of the cotyledons, the leaves, the fruit, the seed sizes, seed surface and pollen pores diameter: A. blitum var. blitum, A. blitum emarginatus and A. blitum oleraceus (see Description). However, their taxonomic ranks remain uncertain.

The subspecies oleraceus is a cultigen form that rarely occurs in the wild in Europe or North America and its native distribution range is not known. Consequently, it could be argued that subsp. oleraceus should not have a taxanomic identity.

The taxa blitum and emarginatus have different origin and Iamonico (personal communication, 2013) suggests that they should be classed as species to reflect their evolutionary histories.

The specific name 'lividus' means 'red' while 'blitum' translates as 'tasteless herb'.

Description

A. blitum is a monoecious annual weed. It grows between 10 and 80 cm tall, sometimes reaching 90 cm.

Stems are prostrate or ascending; sometimes erect, sometimes radiating from base and forming mats; glabrous, green to brown (occasionally reddish), usually highly-branched.

Leaves are usually green, ovate, elliptic to rhombic (see the subspecies descriptions below for the size of the leaves), margins entire, apex emarginate to bilobed (sometimes mucronate), base obtuse or cuneate, glabrous, petioled (petiole 1.0–4.0 cm long).

Synflorescences arranged in axillary glomerules and in terminal spike-like (excepting some forms of the subsp. emarginatus without a terminal spike-like synflorescence), green or brown. Floral bracts, greenwish, ovate [(0.4–)0.8–1.0 by 0.4−0.9 mm], 33-50% shorter than the perianth, acute, margin entire, glabrous. Staminate flowers with 3 tepals, ovate to lanceolate; stamens 3. Pistillate flowers with 3 tepals, lanceolate or linear, elliptic to obovate or spatulate [(0.8−)1.4–1.7(–2.0) by 0.5–1.1(−1.4) mm], with acute apex; stigmas (2−)3.

Pollen grains are small (18–28 μm diameter), have more than 18 uniformly distributed pores (pantoporate), and are covered with granules or spinules, which ensure adherence to the stigma hairs.

Fruit reddish-brown to brown-yellowish, subglobose to elipsoidal (see the subspecies descriptions below for the size of the fruit) as long as or longer than the perianth (in this latter case the length < 2 times of the width), smooth or slightly rugose, indehiscent.

Seed lenticular (see the subspecies descriptions below for diameters), black, brownish-black or dark-reddish, smooth, shiny.

Townsend (1988) indicated that there are more than three perianth segments (0.75 - 2 mm long) mainly in cultivated forms. The capsule is 1.25 - 2.5 mm long. Seeds 1 - 1.75 mm.

The recognized subspecies (blitum, emarginatus and oleraceus) mainly differ each other in cotyledon size, leaf size, fruit length, seed diameter, seed surface and pollen pore diameter. Specifically:

Amaranthus blitum subsp. blitum

Cotyledons with rounded to truncate apex, 9–18 by 3–6 mm; leaf blade size (3.0−)3.5−9.0 by 1.5−6.2 cm; length of the fruit 1.9−3.5 mm; seed diameter 1.1−1.8 mm; seed with minutely punctiform surface and diameter 1.1-1.2 mm; pollen grains with pores of 2.4–3.3 μm.

Amaranthus blitum subsp. emarginatus

Cotyledons with acute apex, 6–7 by 3–6 mm; leaf blade size 1−3.5(−4.5) by (0.5−)0.8−2.5 cm; length of the fruits (1.2−)1.4−1.8(−1.9) mm; seed diameter 0.7−1.1 mm; seed with marginal zone more evidently sculptured; pollen grains with pores of 1.6–1.9 μm.

Amaranthus blitum subsp. oleraceus

Cotyledons with rounded to truncate apex, 9–18 by 3–6 mm; leaf blade size (3.0−)3.5−9.0 by 1.5−6.2 cm; length of the fruit 1.9−3.5 mm; seed diameter 1.1−1.8 mm; seed with smooth surface and diameter 1.2-1.7(-1.9) mm; pollen grains with pores of 2.4–3.3 μm.

Distribution

The native ranges of the three subspecies (blitum, emarginatus and oleraceus) are different, although the taxa have been artificially dispersed all over the world and the original distribution ranges are now blurred. Since the infraspecific classification is yet little known, the distribution table is of A. blitum s.l., without indicating subspecies.

Amaranthus blitum subsp. blitum

Native to Mediterranean area, Europe and North Africa. Alien in North America (Costea et al., 2001, Mosyakin and Robertson 2003). It is also recorded in Asia (Bojian et al., 2003).

Amaranthus blitum subsp. emarginatus

Native to tropical America. It is considered introduced in the warm temperate regions of North America and Europe.

Amaranthus blitum subsp. oleraceus

The origin of this taxon remains uncertain. It is probably originated from a group of the subsp. blitum and is used as cultivated vegetable (e.g. Costea et al., 2001). It rarely occurs in the wild in North America and Europe.

Distribution Table

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Habitat

A. blitum is a weed of the tropics and warm temperate areas. It is found on arable land, river banks, sandy soils and man-made habitats (waste places, roadsides, railways, gardens and orchards, especially on fertile soils).

A. blitum subsp. emarginatus seems to need a warmer climate than A. blitum subsp. blitum (Costea et al., 2003).

Hosts/Species Affected

Host Plants and Other Plants Affected

Biology and Ecology

Reproductive Biology

A. blitum is an annual species, reproducing by seed. The flowers are small, green and unattractive. Flowering time generally ranges from summer to winter.

A. blitum is predominantly wind-pollinated. As with other Amaranthus species, seed production is high.

Germination occurs after imbibition, when the radicle penetrates the micropyle and emerges from the seed. The hypocotyl then elongates, pushing the seed out of the soil. During movement through the soil the cotyledons and the epicotyl are protected by the seed coat (Costea et al., 2003).

Physiology and Phenology

In a study by Teitz et al. (1990), the optimum temperature for germination was found to be 35°C. Germination was inhibited at 40°C. Percentage germination of A. blitum seeds was 84% and 49% for 65 and 85 days after sowing, respectively. Seeds germinated better in light regardless of number of days after sowing. Sodium hypochlorite, ethephon, sulphuric acid and giberellic acid all promoted germination in dark conditions (Teitz et al., 1990).

The emergence of seedlings was delayed and considerably reduced in the case of crust formation and muddy soils (Gaspar et al., 2001).

The dormancy of the seeds is high and can be up to 12 months; however, viability was largely lost after 2.5 years in soil (Takabayashi and Nakayama, 1981). In Indonesia, viability was reduced by approximately 50% after 1 year’s dry storage (Purwanto and Poerba, 1990).

Nakatani and Kusanagi (1991) confirmed that in Japan, A. blitum behaves as a day-neutral plant. Simbolon and Sutarno (1986) studied responses of Amaranthus spp. to reduced light intensity and found all those studied, including A. blitum, to be moderately tolerant of shade.

Noguchi and Nakayama (1978) studied the response of A. blitum to fertilizer. Relative growth rate was increased by fertilizer up to 51 days. Lack of fertilizer delayed flowering.

Natural enemies

Means of Movement and Dispersal

The fruits and seeds of A. blitum are able to float and can be dispersed by rain drops or streamlets caused by rain, surface irrigation or water courses.

Impact

A. blitum is listed by Holm et al. (1979) as a serious or principal weed in ten countries, mainly across Europe and Asia but also including Nigeria and Mozambique. It occurs in a wide range of field and horticultural crops, grassland, orchards, plantations and vineyards. It appears to be especially troublesome in Japan, where it is one of the three main weeds of warmer upland farms (Takabayashi and Nakayama, 1981), and in the USA. It has become more important in Malaysian plantations with the development of biotypes resistant to paraquat. In Minais Gerais province, Brazil, it is among the five most common weeds of coffee (Laca-Buendia and Brandao, 1994).

It survives passage through the digestive tracts of cattle and may be spread with contaminated dung (Takabayashi et al., 1979). There are also reports of fatal poisoning of cattle following grazing on seedlings of A. blitum (Ferreira et al., 1991).

A. blitum subsp. emarginatus potentially impacts on the native riparian herbaceous vegetation in Europe (Walter and Dobes, 2004).
 

Uses

Culinary Uses

A. blitum has been cultivated as a vegetable in Africa, Central and North America (USA and the Caribbean), Asia (China, India, Nepal), Europe (Greece, Italy, Romania) and the South Pacific Islands (Costea et al., 2003). In India it is grown as a leafy vegetable and is known as 'chauli' or 'pokla' (Subbiah and Ramanathan, 1982; Keskar et al., 1983).

The contents of oxalate in leaves (0.08%) and stems (0.15%) increase in plants under stress, but can be reduced by boiling (Abbott and Cambell, 1982).

Nitrate levels in the leaves are equal or superior to spinach (Spinacia oleracea L.). The levels of proteins (22-27%, rich in arginin, tryptophan, isoleucine, and leucine), vitamins (vitamin C and B) and minerals (Ca, Fe, K, Mg, P, S, Al, Zn, Cu) is very high (see Costea et al., 2003). Fibre content is also high.

Its potential as a food crop was reviewed by Turchi (1987).

Medicinal Uses

Fluid extracts are used for throat and mouth ulcers, and due to its astringency, it is recommended for diarrhoea and dysentery (Grieve, 1978). The juice of A. blitum was found to inhibit mutagenesis induced by benzo[a]pyrene, 2-amino-fluorene and 3-amino-1,4 dimethyl-5H-pyridol in Salmonella Typhimurium (Seung et al., 1997).

Uses List

Human food and beverage

• Vegetable

Medicinal, pharmaceutical

• Traditional/folklore

Similarities to Other Species/Conditions

A. blitum, depending on its habit, may be confused with a number of the more prostrate species within the Amaranthus genus (for example, A. graecizans), and also the more erect species such as A. viridis. It differs from all of these in having markedly indented leaf tips. Additionally, it may be distinguished from the prostrate species by the possession of a dense, more or less leafless terminal inflorescence. Of those more erect species with terminal inflorescences, A. viridis is most similar, but has a rounded, rugose fruit hardly exceeding the perianth.

The fruit of A. graecizans has a smooth or slightly rugose surface, like A. blitum. However, the synflorescence in A. graecizans are arranged in axillary glomerules, whereas in A. blitum they are usually arranged as spikes or panicles. In some forms of A. blitum subsp. emarginatus the terminal spike/panicle-like synflorescence is lacking; these forms are easily distinguish from A. graecizans as the leaf apex is emarginate to bilobed, whereas with A. graecizans the leaf apex is usually acute, sometimes obtuse, but never bilobed.

A. blitum may also be confused with members of the subgenus Albersia, particularly A. albus L.

For keys and illustrations to species of Amaranthus see Hafliger and Brun-Hool (undated), Townsend (1985; 1988) and Aellen and Akeroyd (1993). Comparisons of seed morphology are made by Pita and Martinez-Labourde (1992) and Groth et al. (1983). Comparisons of cotyledon morphology are presented by Pita and Mertinez-Labourde (1994).

Prevention and Control

Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

Cultural Control

As a small-seeded annual weed, A. blitum is readily controlled by conventional tillage methods at the seedling stage.

Chemical Control

A. blitum is susceptible to most standard herbicides for annual broad-leaved species, including, for example, metolachlor, metazachlor, linuron, pendimethalin, prometryne, terbutryne, ethofumesate, thiobencarb, oxyfluorfen, lactofen, imazethapyr, amidosulfuron, bentazon, bromoxynil and glyphosate. It is moderately susceptible to 2,4-D and MCPA (Mamarot and Rodriguez, 1997). It was not well controlled by bromacil in Japan (Takahashi et al., 1977), bentazon in Belgium (van Himme et al., 1986), 2,4-D or glufosinate in Malaysia (Itoh et al., 1992), nor by triazines in Belgium (Bulcke and van Himme, 1989). The latter authors state that they could not confirm the development of triazine resistance in this species, while in Switzerland, poor control of A. blitum was attributed to the rapid inactivation of atrazine in acid soils (Maigre, 1991). Resistance to paraquat, however, has developed in Malaysia (Itoh et al., 1992), while in Korea, it is regarded as 'tolerant' (Kang and Shim, 1995). Manley et al. (1996) conclude that in northeastern USA, A. blitum is naturally tolerant of nicosulfuron and may have developed resistance to imazethapyr.

Gaps in Knowledge/Research Needs

The nomenclature of A. blitum is quite confused and further molecular and biogeographical studies are needed to resolve it.

References

Aellen P; Akeroyd JR, 1993. Amaranthus L. In: Tutin TG, Burges NA, Chater AO, Edmondson JR, Heywood VH, Moore DM, Valentine DH, Walters SM, Webb DA, eds. Flora Europaea. Volume 1. Psilotaceae to Platanaceae. 2nd edition. Cambridge, UK: Cambridge University Press, 130-132.

Aellen PL, 1972. Flora Iranica [ed. by Rechinger, K. H.]. Graz, Austria: Akademische Druck, 172 pp.

Al Khulaidi AWA, 2000. Flora of Yemen., Yemen.

Anton AM; Zoluaga FO, 2013. Vascular plants of the Argentine Republic. (Plantas Vasculares de la Republica Argentina.) Flora Argentina. www.floraargentina.edu.ar

Behrens R, 1973. Influence of pre- and post-treatment relative humidity on the phytotoxicity of 2,4-D. Proceedings of the North Central Weed Control Conference, 28:65-66

Bulcke R; Himme Mvan, 1989. Resistance to herbicides in weeds in Belgium. Importance and perspectives on herbicide-resistant weeds. Proceedings of a meeting of the EC Experts' Group, Tollose, Denmark, 15-17 November 1988 [edited by Cavalloro, R.; Noye, G.] L-2985, Luxembourg; Office for Official Publications of the European Community, No. EUR 11561 EN:31-39

Carretero JL, 1990. Amaranthus L. Flora Iberica [ed. by Castroviejo, S. \Lainz, M. \Lopez Gonzales, G. \Montserrat, P. \Munoz Garmendia, F. \Paiva, J. \Villar, L.]. Madrid, Spain: Real Botanical Garden, 559-569.

Chaudhary SA; Parker C; Kasasian L, 1981. Weeds of Central, Southern and Eastern Arabian Peninsula. Tropical Pest Management, 27(2):181-190.

CJBG (Conservatoire et Jardin Botaniques de la Ville de Genève); SAMBI (South African National Biodiversity Institute), 2012. African Plants Database (version 3. 4.0). http://www.ville-ge.ch/musinfo/bd/cjb/africa/index.php

Conn BJ; Lee LL; Kiapranis R, 2004. PGNplants database: Plant collections from Papua New Guinea. PGNplants database. http://www.pgnplants.org/PGNplantbase

Danin A, 2012. Flora of Israel online. Jerusalem, Israel: The Hebrew University of Jerusalem. http://flora.huji.ac.il/browse.asp

Davis PH, 1965-1988. Flora of Turkey and the east Aegean islands. Flora of Turkey and the east Aegean islands. unpaginated.

Dmitrieva SA, 1986. Chromosome numbers of some species of vascular plants from Belorussia. Botanicheskii Zhurnal, 71(8):1145-1147

Dusky JA; Stall WM, 1996. Evaluation of imazethapyr for weed control in leafy vegetable crops. Weed Technology, 10(2):253-257; 28 ref.

eFloras, 2012. Flora of China. Flora of China. eFloras. http://www.efloras.org/flora_page.aspx?flora_id=2

Fennane M; Ibn Tattou M; Mathez J; Ouyahya Oualidi AJEl, 1999. Flore pratique du Maroc 1. Trav. Inst. Sci., Serie Bot, 36.

Ferreira JLM; Riet-Correa F; Schild AL; Méndez MDC, 1991. Poisoning of cattle by Amaranthus spp. (Amaranthaceae) in Rio Grande de Sul, southern Brazil. Pesquisa Veterinária Brasileira, 11(3/4):49-54; 22 ref.

Floc'h ELe; Boulos L; Vela E, 2011. Flora of Tunisia. (Catalogue synonymique commente de la Flore de Tunisie.) Catalogue of the Flora of Tunisia. Tunis, Tunisia.

Flora of North America, 2013. Flora of North America. FNA. http://www.efloras.org/flora_page.aspx?flora_id=1

Funk V; Hollowell T; Berry P; Kelloff C; Alexander SN, 2007. Checklist of the plants of the Guiana Shield (Venezuela: Amazonas, Bolivar, Delta Amacuro; Guyana, Surinam, French Guiana). Contributions from the United States National Herbarium, 584 pp.

Giannopolitis CN, 1981. Amaranthus weed species in Greece: dormancy, germination and response to pre-emergence herbicides. Annales de l'Institut Phytopathologique Benaki, 13(1):80-91

Greuter W; Burdet and Long HG, 1984. Med-checklist. Pteridophyta, Gymnospermae, Dicotyledones (Acanthaceae-Cneoraceae) 1 [ed. by Greuter, W. \Burdet and Long, H. G.]. Geneva, Switzerland: Conservatoire and Botanical Garden.

Groth D; Boaretto MR; Silva RN da, 1983. Seed, fruit and plant morphology in weeds of several crops. Revista Brasileira de Sementes, 5(3):151-182

Hafliger E; Brun-Hool J, unda. 23. Amarantus L. pigweed. Documenta Ciba-Geigy.

Hansen A; Sunding P, 1993. Checklist of vascular plants. 4th revised edition. Flora of Macaronesia. Oslo, Norway: Sommerfeltia.

Himme M van; Bulcke R; Stryckers J, 1986. Nursery crops: dwarf pome fruits. Mededeling van het Centrum voor Onkruidonderzoek van de Rijksuniversiteit Gent, No.44:114-117

Holm LG; Pancho JV; Herberger JP; Plucknett DL, 1979. A geographical atlas of world weeds. New York, USA: John Wiley and Sons, 391 pp.

Hutchinson J; Dalziel JM; Keay RWJ, 1954. Flora of West Tropical Africa. Volume 1, Part 1, 2nd edition. London, UK: Crown Agents.

Hyde MA; Wursten BT; Ballings P, 2013. Flora of Zimbabwe. http://www.zimbabweflora.co.zw

Itoh K; Azmi M; Ahmad A, 1992. Paraquat resistance in Solanum nigrum, Crassocephalum crepidioides, Amaranthus lividus and Conyza sumatrensis in Malaysia. Proceedings of the 1st International Weed Control Congress. Melbourne, Australia; Weed Science Society of Victoria, 2:224-228

Jonsell; (ed) B, 2001. Chenopodiaceae to Fumariaceae 2. Flora Nordica. Stockolm, Sweden: Swedish Royal Academy of Sciences.

Kang BH; Shim SI, 1995. Paraquat toxicity in weed species: difference in physiological responses between tolerant and susceptible species. Korean Journal of Weed Science, 15(3):224-231

Keskar BG; Bhore DP; Maslekar SR, 1983. A note on effects of nitrogen on yield of chaulai (Amaranthus blitum L.). Haryana Journal of Horticultural Sciences, 12:241-243.

Laca-Buendia JP; Brandao M, 1994. Survey and quantitative analysis of weeds occurring in coffee plantations in areas formerly occupied by cerrado in Triangulo Mineiro and Alto Paranaiba. Daphne, Revista do Herba^acute~rio PAMG da EPAMIG, 4(4):71-76; 13 ref.

Lorenzi H, 1982. Weeds of Brazil, terrestrial and aquatic, parasitic, poisonous and medicinal. (Plantas daninhas de Brasil, terrestres, aquaticas, parasitas, toxicas e medicinais.) Nova Odessa, Brazil: H. Lorenzi, 425 pp.

Madhusoodanan KJ; Nazeer MA, 1983. Comparative morphology of the somatic karyotypes of vegetable amaranths and its phylogenetic significance. Cytologia, 48(2):237-244.

Maigre D, 1991. Availability and efficacy of atrazine in acid soils: the Ticino case. Revue Suisse d'Agriculture, 23(3):167-171

Mamarot J; Rodriguez A, 1997. Sensibilité des Mauvaises Herbes aux Herbicides. 4th edition. Paris, France: Association de Coordination Technique Agricole.

Manley BS; Wilson HP; Hines TE, 1996. Smooth pigweed (Amaranthus hybridus) and livid amaranth (A. lividus) response to several imidazolinone and sulfonylurea herbicides. Weed Technology, 10(4):835-841; 22 ref.

Marchioretto MS, 2013. Flora of Brazil (Amaranthus in Lista de Especie da Flora do Brasil). Rio de Janeiro, Brazil: Botanical Garden of Rio de Janeiro. http://floradobrasil.jbrj.gov.br/jabot/floradobrasil/FB101616

Marhold K; Hindák F, 1998. List of the vascular plants of Slovakia (Zoznam nizsich a vyssich rastlín Slovenska). Bratislava, Slovakia.

Martincic A, 1999. Mala Flora Slovenije. Tehniska Zalozba Slovenije, Ljubljana.

Micevski K, 1995. Flora of the Republic of Macedonia, 1(3). Skopje, Macedonia: Macedonian Academy of Sciences and Arts.

Missouri Botanical Garden, 2013. Tropicos database. St Louis, USA: Missouri Botanical Garden. http://www.tropicos.org/

Morros ME; Trujillo B; Ponce M, 1990. Description of the genus Amaranthus L. with 3 new records for Venezuela and a key for the species. Ernstia, 58-59-60:45-51

Nakatani K; Kusanagi T, 1991. Effect of photoperiod and temperature on growth characteristics, especially heading or flower bud appearance of upland weeds. Weed Research (Tokyo), 36(1):74-81; 23 ref.

Nikolic T, 2006. Flora Croatica. (Flora Croatica baza podataka.) Flora Croatica Database [ed. by Nikolic, T.]. http://hirc.botanic.hr/fcd

Noguchi K; Nakayama K, 1978. Effects of fertilization on growth of main upland weeds. Weed Research, Japan, 23(4):175-180

Numata M; Yoshizawa N, 1975. Weed flora of Japan. Japan Association for the Advancement of Phyto-Regulators. Tokyo, Japan: Zenkoku Noson Kyoiku Kyokai.

Palmer J, 2009. A conspectus of the genus Amaranthus (Amaranthaceae) in Australia. Nuytsia, 19(1):107-128. http://science.dec.wa.gov.au/nuytsia

Parker C, 1992. Weeds of Bhutan. Weeds of Bhutan., vi + 236 pp.

PIER, 2013. Pacific Islands Ecosystems at Risk. Honolulu, Hawaii, USA: HEAR, University of Hawaii. http://www.hear.org/pier/index.html

Pita JM; Martinez-Laborde JB, 1992. Morphometric analysis of seeds in species of the genus Amaranthus L. Proceedings of the 1992 Congress of the Spanish Weed Science Society. Madrid, Spain: Sociedad Espanola de Malherbologia, 193-198

Pita JM; Martinez-Laborde JB, 1994. Morphometric analysis of cotyledons in some species of Amaranthus. Investigacion Agraria, Produccion y Proteccion Vegetales, 9(3):359-365

PROTA, 2012. PROTA4U web database. Grubben GJH, Denton OA, eds. Wageningen, Netherlands: Plant Resources of Tropical Africa. http://www.prota4u.org/search.asp

Purwanto Y; Poerba YS, 1990. Effects of drying, temperature and storage time of Amaranthus spinosus L., A. blitum and A. gracilis seeds. BIOTROP Special Publication, 38:85-93

Pyšek P; Sadlo J; Mandak B, 2002. Catalogue of Alien Plants of the Czech Republic. Preslia, Praha, 74:97-186.

QUEZEL P; SANTA S, 1962. New flora of Algeria and southern desert regions (Nouvelle flore de l'Algérie et des régions désertiques méridionales). Paris : Cent. Natn. Rech. Scient., 1170 pp.

Reed CF, 1977. Economically important foreign weeds. Potential problems in the United States. Agriculture Handbook No. 498. United States Department of Agriculture. Washington D.C., USA: USDA-ARS.

Reiche C, 1911. Flora of Chile, 6(1). Santiago, Chile.

Simbolon H; Sutarno H, 1986. Response of Amaranthus species to various light intensities. Buletin Penelitian Hortikultura, 13(3):33-42

Siverio A; Sobrino E; Rodríguez H; Arévalo JR, 2011. Weeds of golf courses on the island of Tenerife. (Malas hierbas de los campos de golf de la isla de Tenerife.) In: Plantas invasoras resistencias a herbicidas y detección de malas hierbas. XIII Congreso de la Sociedad Española de Malherbología, La Laguna, Spain, 22-24 November 2011 [ed. by Arévalo JR, Fernández S, López F, Recasens J, Sobrino E]. Madrid, Spain: Sociedad Española de Malherbología (Spanish Weed Science Society), 83-86.

Stewart RR, 1972. Flora of West Pakistan. Karachi, Pakistan: Fakhri Printing Press.

Strid A; Tan K, 1997. Flora Hellenica, Vol. 1. Koenigstein, Germany; Koeltz Scientific Books.

Stroud A; Parker C, 1989. A Weed Identification Guide for Ethiopia. Rome, Italy: Food and Agriculture Organization.

Subbiah K; Ramanathan KM, 1982. Influence of N and K2O on the crude protein, carotene, ascorbic acid and chlorophyll contents of Amaranthus. South Indian Horticulture, 30(2):82-86.

Swarbrick JT, 1997. Weeds of the Pacific Islands. Technical paper No. 209. Noumea, New Caledonia: South Pacific Commission.

Tackholm V, 1974. Students' Flora of Egypt. 2nd edition. Cairo, Egypt: University of Cairo.

Takabayashi M; Kubota T; Abe H, 1979. Dissemination of weed seeds through cow fpces. JARQ [Japan Agricultural Research Quarterly], 13(3):204-207.

Takabayashi M; Nakayama K, 1978. Longevity of buried weed seeds in soil. Weed Research, Japan, 23(1):32-36

Takabayashi M; Nakayama K, 1981. The seasonal change in seed dormancy of main upland weeds. Weed Research, Japan, 26(3):249-253

Takahashi K; Sakai Y; Harada Y; Hirose K, 1977. Effect of ten years' application with bromacil in citrus (Satsuma mandarin) orchard. 1. Effects of bromacil on annual variations of weed species and population. Weed Research, Japan, 22(4):198-202

Taxon, 1984. Nomenclature. Report of the Committee for Spermatophyta: Proposal 540. Taxon, 33:298.

Teitz AY; Gorski SF; McDonald MB, 1990. The dormancy of livid amaranth (Amaranthus lividus L.) seeds. Seed Science and Technology, 18(3):781-789

Tela Botanica, 2012. Tela Botanica. http://www.tela-botanica.org/site:accueil

Townsend CC, 1985. Amaranthaceae. In: Polhill RM, ed. Flora of Tropical East Africa. Rotterdam, Netherlands: A.A. Balkema, 1-2, 20-24, 35-36.

Townsend CC, 1988. Amaranthaceae. In: Launert E, ed. Flora Zambesiaca. Volume 9, Part 1. London, UK: Flora Zambesiaca Management Committee, 28-133.

Turchi F, 1987. Amaranths: a rarely recorded crop with significant prospects. Rivista di Agricoltura Subtropicale e Tropicale, 81:89-116.

Tutin TG; Burges NA; Chater AO; Edmonson JR; Heywood VH; Moore DM; Valentine DH; Walters SM; Webb DA, 1993. Flora Europaea. Volume 1. 2nd edition. Cambridge, UK: Cambridge University Press. World Wide Web page at http://www.rbge.org.uk/forms/fe.html.

Vencill WK; Hatzios KK; Wilson HP, 1990. Absorption, translocation, and metabolism of C-clomazone in soyabean (Glycine max) and three Amaranthus weed species. Journal of Plant Growth Regulation, 9(3):127-132

Verloove F, 2006. Catalogue of neophytes in Belgium (1800-2005). Scripta Botanica Belgica, 39: 89 pp. http://alienplantsbelgium.be/sites/alienplantsbelgium.be/files/tabel_2.pdf

Walter J; Dobes C, 2004. Morphological characters, geographic distribution and ecology of neophytic Amaranthus blitum L. subsp. emarginatus in Austria. Annals of the Natural History Museum, Vienna, 105(B). Vienna, Austria: Annals of the Natural History Museum, 645-672.

Wang ZR, 1990. Farmland Weeds in China. Beijing, China: Agricultural Publishing House.

Waterhouse DF, 1993. The Major Arthropod Pests and Weeds of Agriculture in Southeast Asia. ACIAR Monograph No. 21. Canberra, Australia: Australian Centre for International Agricultural Research, 141 pp.

Wisskirchen R; Haeupler H, 1998. .

Wohlgemuth T; Boschi andLongatti KP, 2001. .

Distribution References

Aellen P, Akeroyd JR, 1993. Volume 1. Psilotaceae to Platanaceae. 2nd edition. In: Flora Europaea. Volume 1. Psilotaceae to Platanaceae, Volume 1 (2nd edition) [ed. by Tutin TG, Burges N, Chater AO, Edmondson JR, Heywood VH, Moore DM, Valentine DH, Walters SM, Webb DA]. Cambridge, UK: Cambridge University Press. 130-132.

Aellen PL, 1972. (Flora Iranica)., [ed. by Rechinger KH]. Graz, Austria: Akademische Druck. 172 pp.

Al Khulaidi AWA, 2000. Flora of Yemen., Yemen: 111.

Anton AM, Zoluaga FO, 2013. Vascular plants of the Argentine Republic. (Plantas Vasculares de la Republica Argentina). In: Flora Argentina, http://www.floraargentina.edu.ar

Behrens R, 1973. Influence of pre- and post-treatment relative humidity on the phytotoxicity of 2,4-D. In: Proceedings of the North Central Weed Control Conference. [Proceedings of the North Central Weed Control Conference.], 65-66.

CABI, Undated. Compendium record. Wallingford, UK: CABI

CABI, Undated a. CABI Compendium: Status inferred from regional distribution. Wallingford, UK: CABI

CABI, Undated b. CABI Compendium: Status as determined by CABI editor. Wallingford, UK: CABI

Carretero JL, 1990. (Amaranthus L. Flora Iberica)., [ed. by Castroviejo S, Lainz M, Lopez Gonzales G, Montserrat P, Munoz Garmendia F, Paiva J, Villar L]. Madrid, Spain: Real Botanical Garden. 559-569.

Chaudhary S A, Parker C, Kasasian L, 1981. Weeds of central, southern and eastern Arabian Peninsula. Tropical Pest Management. 27 (2), 181-190.

Conn BJ, Lee LL, Kiapranis R, 2004. PGNplants database: Plant collections from Papua New Guinea. In: PGNplants database, http://www.pgnplants.org/PGNplantbase

Danin A, 2012. Flora of Israel online., Jerusalem, Israel: The Hebrew University of Jerusalem. http://flora.huji.ac.il/browse.asp

Dmitrieva S A, 1986. Chromosome numbers of some species of vascular plants from Belorussia. Botanicheskiĭ Zhurnal. 71 (8), 1145-1147.

Dusky J A, Stall W M, 1996. Evaluation of imazethapyr for weed control in leafy vegetable crops. Weed Technology. 10 (2), 253-257.

Flora of North America, 2013. Flora of North America., FNA. http://www.efloras.org/flora_page.aspx?flora_id=1

Funk V, Hollowell T, Berry P, Kelloff C, Alexander S N, 2007. Contributions from the United States National Herbarium, Washington, USA: Department of Systematic Biology - Botany, National Museum of Natural History, Smithsonian Institution. 55, 584 pp.

Greuter W, Burdet, Long HG, 1984. Med-checklist. Pteridophyta, Gymnospermae, Dicotyledones (Acanthaceae-Cneoraceae) 1., [ed. by Greuter WB, Long HG]. Geneva, Switzerland: Conservatoire and Botanical Garden.

Hansen A, Sunding P, 1993. Checklist of vascular plants. 4th revised edition. In: Flora of Macaronesia, Oslo, Norway: Sommerfeltia.

Holm L, Pancho J V, Herberger J P, Plucknett D L, 1979. A geographical atlas of world weeds. New York, Chichester (), Brisbane, Toronto, UK: John Wiley and Sons. xlix + 391 pp.

Hutchinson J, Dalziel J M, Keay R W J, 1954. Flora of West Tropical Africa. Volume 1, Part 1. London, UK: Crown Agents.

Hyde MA, Wursten BT, Ballings P, 2013. Flora of Zimbabwe., http://www.zimbabweflora.co.zw

Itoh K, Azmi M, Ahmad A, 1992. Paraquat resistance in Solanum nigrum, Crassocephalum crepidioides, Amaranthus lividus and Conyza sumatrensis in Malaysia. In: Proceedings of the 1st International Weed Control Congress. [Proceedings of the 1st International Weed Control Congress.], Melbourne, Australia: Weed Science Society of Victoria. 224-228.

Kang B H, Shim S I, 1995. Paraquat toxicity in weed species: difference in physiological responses between tolerant and susceptible species. Korean Journal of Weed Science. 15 (3), 224-231.

Lorenzi H, 1982. Plantas daninhas de Brasil, terrestres, aquaticas, parasitas, toxicas e medicinais. Nova Odessa, Brazil: H. Lorenzi. 425 pp.

Madhusoodanan K J, Nazeer M A, 1983. Comparative morphology of the somatic karyotypes of vegetable amaranths and its phylogenetic significance. Cytologia. 48 (2), 237-244. DOI:10.1508/cytologia.48.237

Manley B S, Wilson H P, Hines T E, 1996. Smooth pigweed (Amaranthus hybridus) and livid amaranth (A. lividus) response to several imidazolinone and sulfonylurea herbicides. Weed Technology. 10 (4), 835-841.

Marchioretto MS, 2013. Flora of Brazil (Amaranthus in Lista de Especie da Flora do Brasil)., Rio de Janeiro, Brazil: Botanical Garden of Rio de Janeiro. http://floradobrasil.jbrj.gov.br/jabot/floradobrasil/FB101616

Marhold K, Hindák F, 1998. List of the vascular plants of Slovakia. (Zoznam nizsich a vyssich rastlín Slovenska)., Bratislava, Slovakia:

Martincic A, 1999. Mala Flora Slovenije., Ljubljana, Tehniska Zalozba Slovenije.

Micevski K, 1995. Flora of the Republic of Macedonia., 1 (3) Skopje, Macedonia: Macedonian Academy of Sciences and Arts.

Missouri Botanical Garden, 2013. Tropicos database., St Louis, USA: Missouri Botanical Garden. http://www.tropicos.org/

Morros M E, Trujillo B, Ponce M, 1990. Description of the genus Amaranthus L. with 3 new records for Venezuela and a key for the species. (Descripción del genero Amaranthus L. con 3 nuevos registros para Venezuela y consiguiente clave para las especies.). Ernstia. 45-51.

Nikolic T, 2006. (Flora Croatica). In: Flora Croatica Database, [ed. by Nikolic T]. http://hirc.botanic.hr/fcd

Palmer J, 2009. A conspectus of the genus Amaranthus (Amaranthaceae) in Australia. Nuytsia. 19 (1), 107-128. http://science.dec.wa.gov.au/nuytsia

Parker C, 1992. Weeds of Bhutan. Thimphu, Bhutan: National Plant Protection Centre. vi + 236 pp.

PIER, 2013. Pacific Islands Ecosystems at Risk., Honolulu, Hawaii, USA: HEAR, University of Hawaii. http://www.hear.org/pier/index.html

PROTA, 2012. PROTA4U web database., [ed. by Grubben GJH, Denton OA]. Wageningen, Netherlands: Plant Resources of Tropical Africa. http://www.prota4u.org/search.asp

Quezel P, Santa S, 1962. New flora of Algeria and southern desert regions. Paris : Cent. Natn. Rech. Scient. 1170 pp.

Reed C F, 1977. Economically important foreign weeds. Potential problems in the United States. Washington, D.C. USA: United States Department of Agriculture. 746 pp.

Reiche C, 1911. Flora of Chile., 6 (1) Santiago, Chile:

Siverio A, Sobrino E, Rodríguez H, Arévalo J R, 2011. Weeds of golf courses on the island of Tenerife. (Malas hierbas de los campos de golf de la isla de Tenerife.). In: Plantas invasoras resistencias a herbicidas y detección de malas hierbas. XIII Congreso de la Sociedad Española de Malherbología, La Laguna, Spain, 22-24 November 2011. [ed. by Arévalo J R, Fernández S, López F, Recasens J, Sobrino E]. Madrid, Spain: Sociedad Española de Malherbología (Spanish Weed Science Society). 83-86.

Stewart R, 1972. An annotated catalogue of the vascular plants of West Pakistan and Kashmir. In: Flora of West Pakistan. [ed. by Nasir E, Ali S I]. Karachi, Pakistan: Fakhri Printing Press.

Strid A, Tan K, 1997. Flora Hellenica., 1 Koenigstein, Germany: Koeltz Scientific Books.

Stroud A, Parker C, 1989. A weed identification guide for Ethiopia. In: A weed identification guide for Ethiopia. Rome, Italy: Food and Agriculture Organization. 278 pp.

Swarbrick JT, 1997. Weeds of the Pacific Islands. In: Technical paper No. 209, Noumea, New Caledonia, South Pacific Commission.

Tackholm V, 1974. Students' Flora of Egypt., Cairo, Egypt: University of Cairo.

Teitz A Y, Gorski S F, McDonald M B, 1990. The dormancy of livid amaranth (Amaranthus lividus L.) seeds. Seed Science and Technology. 18 (3), 781-789.

Tela Botanica, 2012. (Tela Botanica)., http://www.tela-botanica.org/site:accueil

Townsend CC, 1985. Amaranthaceae. In: Flora of Tropical East Africa, [ed. by Polhill RM]. Rotterdam, Netherlands: A.A. Balkema. 1-2, 20-24, 35-36,

Townsend CC, 1988. Amaranthaceae. In: Flora Zambesiaca, 9 (1) [ed. by Launert E]. London, UK: Flora Zambesiaca Management Committee. 28-133.

Vencill W K, Hatzios K K, Wilson H P, 1990. Absorption, translocation, and metabolism of 14C-clomazone in soyabean (Glycine max) and three Amaranthus weed species. Journal of Plant Growth Regulation. 9 (3), 127-132. DOI:10.1007/BF02041951

Verloove F, 2006. Catalogue of neophytes in Belgium (1800-2005). Scripta Botanica Belgica. 89 pp.

Walter J, Dobes C, 2004. Morphological characters, geographic distribution and ecology of neophytic Amaranthus blitum L. subsp. emarginatus in Austria. In: Annals of the Natural History Museum, Vienna, 105 (B) Vienna, Austria: Annals of the Natural History Museum. 645-672.

Waterhouse D F, 1993. The major arthropod pests and weeds of agriculture in Southeast Asia. Canberra, Australia: ACIAR. v + 141 pp.

Contributors

22/09/98 Original text by:

Chris Parker, Consultant, UK

31/08/13 Updated by:

Duilio Iamonico, University of Rome Sapienza, Italy

Distribution Maps