Common Names in English:
, or lianas. Leaves alternate or opposite, entire, exstipulate
. Flowers small, bisexual
, or sterile
and reduced, subtended by 1 membranous bract and 2 bracteoles, solitary or aggregated in cymes. Inflorescences elongated or condensed spikes (heads
, or thyrsoid
structures of varying complexity. Bracteoles membranous or scarious
. Tepals 3-5, membranous, scarious or subleathery, 1-, 3-, 5-, or 7(-23) -veined. Stamens as many as tepals and opposite these, rarely fewer than tepals; filaments
into a cup
or ± entirely into a tube
, filament lobes present or absent, pseudostaminodes present or absent; anthers
(1- or) 2-loculed, dorsifixed
, introrsely dehiscent
. Ovary superior, 1-loculed; ovules 1 to many; style persistent
, short and indistinct or long and slender; stigma capitate, penicillate
, 2-lobed or forming 2 filiform
branches. Fruit a dry utricle or a fleshy
capsule, indehiscent, irregularly bursting, or circumscissile. Seeds lenticular
, subglobose, or shortly cylindric
About 70 genera and 900 species: worldwide; 15 genera (one introduced ) and 44 species (three endemic, 14 introduced) in China.
Morphology of the androecium, perianth (tepals), and the inflorescence has traditionally been used to circumscribe genera and tribes . Pseudostaminodia are interstaminal appendages with variously shaped apices. Filament appendages are the lateral appendages of filaments (one on each side) . The basic structure of the inflorescence is the cyme (branchlets arising from the bracteole axils, the bracteoles serving as bracts for upper flowers), which can be reduced to one flower with two bracteoles and a bract. Units of dispersal vary considerably (capsules opening with lower part persistent, flower and bracteoles falling together, or cymose partial inflorescences breaking off above bract) and can be characteristic for genera. Several genera possess long trichomes serving dispersal at the base of the tepals.
Herbs, usually annual
, rarely perennial
, monoecious (subg. Amaranthus and Albersia) or dioecious (subg. Acnida), glabrous
. Stems erect
, or prostrate
, usually branched, occasionally simple
or nearly so; without nodal
spines (except in A. spinosus ). Leaves alternate, petiolate
, lanceolate, oblanceolate
, or orbiculate to linear
to narrowly cuneate, margins
usually entire, usually plane
, slightly undulate
, or crispate
, rarely undulate-erose, apex acute, obtuse
, or emarginate
, usually mucronulate
. Inflorescences terminal
or exclusively terminal, compound
dichasia arranged in spikes, thyrses
, panicles, or glomerules
of terminal inflorescences often subtended by reduced leaves (pseudobracts), each dichasium unit
subtended by persistent
bracts. Bracts ovate, lanceolate, linear, subulate
, deltate, or broadly triangular (in A. acanthochiton), or proximal
bracts modified into spines (in A. spinosus) ; bracts of pistillate
flowers not keeled
(keeled in A. scleropoides and A. crassipes) ; bracteoles absent or 1-2. Flowers unisexual
. Pistillate flowers: tepals absent or (1-) 3-5, distinct
in proximal 1/3 in A. polygonoides, equal or outer tepals larger than inner ones, usually membranaceous
, sometimes scarious
at maturity; stamens absent [rudimentary
]; pistil 1; ovule 1; style 0.1-1 mm, or absent; stigmas 2-3(-5), slender. Staminate flowers
: tepals 3-5, equal or subequal
; stamens 3-5, filaments
4-locular, pseudostaminodes absent; pistils absent or rudimentary. Utricles loosely enclosed by inner tepals, occasionally conspicuously 3(-5) -veined, usually globose
, or elongate-ovoid, thin walled, membranaceous, rugose
, glabrous, dehiscence regularly circumscissile, irregularly dehiscent
, or indehiscent. Seeds 1, subglobose or lenticular
, usually smooth
, shiny, sometimes indistinctly puncticulate
; embryo annular
. x = 16, 17.
Species ca. 70 (38 in the flora , including cultivated species) : mostly tropical , subtropical , and warm-temperate zones, some species in temperate zones; some taxa are at present almost worldwide as introduced and naturalized weeds .
Some segregate genera of Amaranthus, in the broad sense, have been proposed and sometimes recognized (see synonymy ). In the present treatment, Amaranthus is accepted in its broad sense. Three subgenera are currently recognized (S. L. Mosyakin and K . R. Robertson 1996) : subg. Acnida, subg. Amaranthus, and subg. Albersia.
Morphologic terminology in Amaranthus, as used in different floristic and taxonomic treatments, is rather confusing, especially regarding the terms applied to inflorescences and flowers. In the present treatment, we follow the traditional inflorescence terminology only for brevity and convenience; see T. A. Fedorova (1997) for a more complex scheme. A flower is subtended by a bract, often termed a "bracteole," and 0-2 lateral bracts, the true bracteoles. Structures that are clearly reduced green leaves subtending portions of the inflorescence are sometimes incorrectly called bracts.
Specimens of Amaranthus are often difficult to identify by someone not familiar with the group. When using the key , look closely at the tips of pistillate inflorescence branches for staminate flowers to determine whether the plant is monoecious or dioecious; this is especially important for some monoecious species that produce few staminate flowers. Also, pistillate plants of dioecious species are usually required for positive identification. Descriptions and measurements of floral parts are given in more detail for pistillate flowers, unless noted otherwise.
Determining the exact distribution of some species of Amaranthus in North America requires additional floristic and taxonomic studies. Because of the weedy life strategies of some Amaranthus species, they may occasionally occur as naturalized weeds or waifs very far from their original areas of distribution. Some of such isolated populations exist only as long as conditions are favorable and may eventually disappear or, vice versa, become expansive and invasive. These factors , together with frequent misidentifications in herbaria and the literature, obscure the distribution patterns of some Amaranthus species in North America. Weedy and introduced species of Amaranthus are often neglected or misidentified by collectors . Consequently, some taxa are known only from scattered localities in various regions of the flora, and their actual distribution may be much wider than present data indicate. Some species have been reported for the flora only as rare, casual , non-naturalized aliens , e.g. , on ballast , or as grain immigrants or wool contaminants, and may not now be present in North America. Because of all these factors, the maps and distribution statements in the treatment show the generalized distribution and may not properly reflect the actual changing distribution patterns of some species, especially those that have expanded their ranges over the decades due to various anthropic factors. In addition to the taxa discussed below, some other South American or Old World species may be found in North America in the future as introduced weeds.
Species of Amaranthus occasionally form interspecific hybrids. Such hybridization seems to be especially important and widespread in cultivated grain-amaranths, in wild representatives of the A. hybridus aggregate, between species of sect. Amaranthus, and between A. tuberculatus and species of sect. Amaranthus. The degree and scope of hybridization in Amaranthus are often overestimated, especially by European authors , and some taxa described as putative hybrids are in fact nonhybrid infraspecific forms of morphologically variable species. Hybrids between more distantly related species, if they occur at all, are usually highly sterile , such as hybrids between taxa of the subgenera Amaranthus and Acnida, or at least show much decreased fertility . There are no verified records of hybrids between representatives of the subgenera Amaranthus and Albersia.
Some species of Amaranthus are cultivated as pseudocereal and leaf-vegetable crops , or as ornamental or fodder plants (J. D. Sauer 1967; D. M. Brenner 1990; J. T. Williams and D. M. Brenner 1995; S. Cheatham et al. 1995). The most commonly cultivated taxa are A. caudatus Linnaeus, A. hypochondriacus Linnaeus, and A. cruentus Linnaeus of American origin , and south Asian A. tricolor Linnaeus. The cultivated species may occur occasionally as escapes near places of cultivation; they cannot be regarded as truly naturalized.
Species of Amaranthus were widely used by prehistoric and modern Native Americans as food, forage for livestock, medicinal plants, and, occasionally, for some other uses, such as face and body paint, ceremonial items, and fuel (S. Cheatham et al. 1995; D. E. Moerman 1998).
- Whittaker & Margulis,1978
- Haeckel, 1866
- Cavalier-Smith, 1981
- Sinnott, 1935 ex Cavalier-Smith, 1998
- Vascular Plants
- Kenrick & Crane, 1997
- Brongniart, 1843
- Takhtajan, 1967
- Takhtajan, 1967
- Perleb, 1826
- Family: Amaranthaceae () - Adanson, 1763 ex A.L. de Jussieu, 1789, nom. cons. - amaranthes, pigweed
- Suborder: Chenopodiineae ()
- Order: Caryophyllales () - Perleb, 1826
- Superorder: Caryophyllanae () - Takhtajan, 1967
- Subclass: Caryophyllidae () - Takhtajan, 1967
- Class: Spermatopsida () - Brongniart, 1843
- Infraphylum: Radiatopses () - Kenrick & Crane, 1997
- Subphylum: Euphyllophytina ()
- Phylum: Tracheophyta () - Sinnott, 1935 ex Cavalier-Smith, 1998 - Vascular Plants
- Subkingdom: Viridaeplantae () - Cavalier-Smith, 1981
- Kingdom: Plantae () - Haeckel, 1866 - Plants
Amaranthus ascendens Loisel. • Amaranthus lividus L. • Amaranthus viridus auct. non L.
: Hornem. Publication
: Hort. Hafn. Suppl. 107.
Name Status: Accepted Name . Synonym: Amaranthus ascendens. Latest taxonomic scrutiny: March 15, 2000.
Name verified on 04-Feb-2003 by ARS Systematic Botanists. Last updated: 29-Oct-2007
Members of the genus Amaranthus
ZipcodeZoo has pages for 91 species, subspecies, varieties, forms, and cultivars in this genus:
A. acanthochiton (Green-Stripe Amaranth) · A. acutilobus (Sharplobe Amaranth) · A. albus (Pigweed) · A. A. caudatus (Love Lies Bleeding) · A. arenicola (Sand Amaranth) · A. australis (Giant Amaranth) · A. bigelovii (Bigelow's Amaranth) · A. blitoides (Mat Amaranth) · A. blitum (Bride Malabar) · A. blitum blitum (Purple Amaranth) · A. blitum var. pseudogracilis (Amaranthus Blitum) · A. brownii (Brown's Amaranth) · A. californicus (California Amaranth) · A. cannabinus (Salt-Marsh Water-Hemp) · A. caudatus (Foxtail Amaranth) · A. caudatus caudatus (Love Lies Bleeding) · A. caudatus 'Fat Spike' (Love-Lies-Bleeding) · A. caudatus 'Pony Tails' (Love-Lies-Bleeding) · A. caudatus 'Viridis' (Green Tassel Flower) · A. chihuahuensis (Chihuahuan Amaranth) · A. crassipes (Clubfoot Amaranth) · A. crispus (Crisp-Leave Amaranth) · A. cruentus (Blood Amaranth) · A. cruentus 'Giant Copperhead' (Mexican Grain Amaranth) · A. cruentus 'Golden Giant' (Mexican Grain Amaranth) · A. cruentus 'Hot Biscuits' (Mexican Grain Amaranth) · A. cruentus 'Marvel Bronze' (Mexican Grain Amaranth) · A. cruentus 'Oeschberg' (Mexican Grain Amaranth) · A. cruentus 'Orange Giant' (Mexican Grain Amaranth) · A. cruentus 'Split Personality' (Mexican Grain Amaranth) · A. cruentus 'Towers Green' (Mexican Grain Amaranth) · A. cruentus 'Towers Red' (Mexican Grain Amaranth) · A. cruentus 'Velvet Curtain' (Mexican Grain Amaranth) · A. deflexus (Argentina Amaranth) · A. dubius (Spleen Amaranth) · A. fimbriatus (Fringed Amaranth) · A. fimbriatus var. denticulatus (Fringed Amaranth) · A. fimbriatus var. fimbriatus (Fringed Amaranth) · A. floridanus (Florida Amaranth) · A. gangeticus 'Greek' (Amaranth) · A. greggii (Gregg's Amaranth) · A. hybridus (Green Amaranth) · A. hybridus cruentus (Green Pigweed) · A. hypochondriacus (Prince's Feather Amaranth) · A. hypochondriacus 'Burgundy' (Amaranth) · A. hypochondriacus 'Green Thumb' (Prince-Of-Wales Feather) · A. hypochondriacus 'Manna De Montana' (Amaranth) · A. hypochondriacus 'Mercado' (Amaranth) · A. hypochondriacus 'Oscar Blanco' (Amaranth) · A. hypochondriacus 'Pygmy Torch' (Prince-Of-Wales Feather) · A. lineatus (Australian Amaranth) · A. mangostanus (Chinese Spinach) · A. muricatus (African Amaranth) · A. obcordatus (Trans Pecos Amaranth) · A. palmeri (Careless Weed) · A. polygonoides (Smartweed Amaranth) · A. powellii (Green Amaranth) · A. pringlei (Pringle's Amaranth) · A. pumilus (Coast Amaranth) · A. retroflexus (Careless Weed) · A. retroflexus 'Fotete' (Green Amaranth) · A. rudis (Common Waterhemp) · A. scleropoides (Bone-Bract Amaranth) · A. spinosus (Calaloo) · A. texensis (Amaranthus) · A. thunbergii (Thunberg's Amaranth) · A. torreyi (Torrey's Amaranthus) · A. tricolor (Chinese Spinach) · A. tricolor var. salicifolius (Flaming Fountain) · A. tricolor 'Aurora' (Chinese Spinach) · A. tricolor 'Cinco De Mayo' (Amaranth) · A. tricolor 'Green Leaf' (Chinese Spinach) · A. tricolor 'Illumination' (Chinese Spinach) · A. tricolor 'New Garnet Red' (Chinese Spinach) · A. tricolor 'Perfecta' (Chinese Spinach) · A. tricolor 'Red Leaf' (Chinese Spinach) · A. tricolor 'Splendens' (Chinese Spinach) · A. tuberculatus (Rough-Fruit Amaranth) · A. viridis (Chinese Spinach) · A. viridis 'All Red' (Amaranth) · A. viridis 'Asia Red' (Amaranth) · A. viridis 'Bayam' (Amaranth) · A. viridis 'Green Pointed Leaf' (Amaranth) · A. viridis 'Green Round Leaf' (Amaranth) · A. viridis 'Red Stripe Leaf' (Amaranth) · A. viridis 'Tender Leaf' (Amaranth) · A. viridis 'White Leaf' (Amaranth) · A. watsonii (Torrey's Amaranthus) · A. wrightii (Wright's Amaranth) · A. 'Magic Fountains Mix' (Amaranthus) · A. 'Opopeo' (Love-Lies-Bleeding)
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- Costea, M. et al. 2001. Notes on some little known Amaranthus taxa (Amaranthaceae) in the United States. Sida 19:979.
- Wisskirchen, R. and Haeupler, H. (1998a): Standardliste der Farn- und Bl&uuml;tenpflanzen Deutschlands, Stuttgart: Ulmer
- Kuan Ke-chien. 1979. Amaranthaceae. In: Kung Hsien-wu & Tsien Cho-po, eds., Fl. Reipubl. Popularis Sin. 25(2): 194241.
- Brenner, D. M. et al. 2000. Genetic resources and breeding of Amaranthus. Pl. Breed. Rev. 19: 227-285.
- Costea, M. and D. A. DeMason. 2001. Stem morphology and anatomy in Amaranthus L. (Amaranthaceae): Taxonomic significance. J. Torrey Bot. Soc. 128: 254-281.
- Costea, M., A. Sanders, and G. Waines. 2001. Preliminary results toward a revision of the Amaranthus hybridus species complex (Amaranthaceae). Sida 19: 931-974.
- Mosyakin, S. L. and K. R. Robertson. 1996. New infrageneric taxa and combinations in Amaranthus L. (Amaranthaceae). Ann. Bot. Fenn. 33: 275-281.
- Sauer, J. D. 1955. Revision of the dioecious amaranths. Madroño 13: 5-46.
- Sauer, J. D. 1967b. The grain amaranths and their relatives: A revised taxonomic and geographic survey. Ann. Missouri Bot. Gard. 54: 103-137.
- Sauer, J. D. 1972b. The dioecious amaranths: A new species name and major range extensions. Madroño 21: 426-434.
- Uline, E. B. and W. L. Bray. 1894. A preliminary synopsis of the North American species of Amaranthus. Bot. Gaz. 19: 267-273, 313-320.
- Brands, S.J. (comp.) 1989-present. The Taxonomicon. Universal Taxonomic Services, Zwaag, The Netherlands. Accessed January 10, 2012.
- USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland. URL (April 25, 2008)
- USDA, NRCS. 2005. The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
- Biodiversity Heritage Library NamebankID: 5886426
- Catalogue of Life Accepted Name Code: ITS-181923
- GRIN Nomen Number: 430519
- Integrated Taxonomic Information System (ITIS) Taxonomic Serial Number (TSN): 181923
- Natural Heritage Network Species Identifier: PDAMA04190
- U.S.D.A. Plant Symbol: AMVI5
- Zipcode Zoo Species Identifier: 18517
- Bojian Bao, Thomas Borsch & Steven E. Clemants "Amaranthaceae". in Flora of China Vol. 5 Page 415. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
- Sergei L. Mosyakin & Kenneth R. Robertson "Amaranthus". in Flora of North America Vol. 4 Page 405, 406, 410. Oxford University Press. Online at EFloras.org. [back]