Hubbry Logo
AmaranthaceaeAmaranthaceaeMain
Open search
Amaranthaceae
Community hub
Amaranthaceae
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Amaranthaceae
Amaranthaceae
Amaranthaceae
View on Wikipedia
from Wikipedia

Amaranthaceae
Amaranthus retroflexus
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Caryophyllales
Family: Amaranthaceae
Juss.
Type genus
Amaranthus
Subfamilies
Synonyms[1]

Chenopodiaceae Vent.

Amaranthaceae (/ˌæmərænˈθeɪsi.iː, -ˌaɪ/ AM-ər-an-THAY-see-ee, -⁠eye) 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,[2][3] making it the most species-rich lineage within its parent order, Caryophyllales.

Description

[edit]

Most species in the Amaranthaceae are annual or perennial herbs or subshrubs; others are shrubs; very few species are vines or trees. Some species are succulent. Many species have stems with thickened nodes. The wood of the perennial stem has a typical "anomalous" secondary growth; only in subfamily Polycnemoideae is secondary growth normal.[3]

The leaves are simple and mostly alternate, sometimes opposite. They never possess stipules. They are flat or terete, and their shape is extremely variable, with entire or toothed margins. In some species, the leaves are reduced to minute scales. In most cases, neither basal nor terminal aggregations of leaves occur.[3]

The flowers are solitary or aggregated in cymes, spikes, or panicles and typically perfect (bisexual) and actinomorphic. Some species have unisexual flowers. Bracts and bracteoles are either herbaceous or scarious. Flowers are regular with an herbaceous or scarious perianth of (one to) mostly five (rarely to eight) tepals, often joined. One to five stamens are opposite to tepals or alternating, inserting from a hypogynous disc, which may have appendages (pseudostaminodes) in some species. The anthers have two or four pollen sacs (locules). In tribe Caroxyloneae, anthers have vesicular appendages. The pollen grains are spherical with many pores (pantoporate), with pore numbers from a few to 250 (in Froelichia).[4] One to three (rarely six) carpels are fused to a superior ovary with one (rarely two) basal ovule.[3] Idioblasts are found in the tissues.

The diaspores are seeds or fruits (utricles), more often the perianth persists and is modified in fruit for means of dispersal. Sometimes even bracts and bracteoles may belong to the diaspore. More rarely the fruit is a circumscissile capsule or a berry. The horizontal or vertical seed often has a thickened or woody seed coat. The green or white embryo is either spirally (and without perisperm) or annular (rarely straight).[3]

Chromosome number

[edit]

The basic chromosome number is (rarely 6) mostly 8–9 (rarely 17).[3]

Phytochemistry

[edit]

Widespread in the Amaranthaceae is the occurrence of betalain pigments. The former Chenopodiaceae often contain isoflavonoids.[3]

In phytochemical research, several methylenedioxyflavonols, saponins, triterpenoids, ecdysteroids, and specific root-located carbohydrates have been found in these plants.[4]

Photosynthesis pathway

[edit]

Although most of the family use the more common C3 photosynthesis pathway, around 800 species are C4 plants; this makes the Amaranthaceae the largest group with this photosynthesis pathway among the eudicots (which collectively includes about 1,600 C4 species).[5] Within the family, several types of C4 photosynthesis occur, and about 17 different types of leaf anatomy are realized. Therefore, this photosynthesis pathway seems to have developed about 15 times independently during the evolution of the family. About two-thirds of the C4 species belong to the former Chenopodiaceae. The first occurrence of C4 photosynthesis dates from the early Miocene, about 24 million years ago, but in some groups, this pathway evolved much later, about 6 (or less) million years ago.[5]

The multiple origin of C4 photosynthesis in the Amaranthaceae is regarded as an evolutionary response to inexorably decreasing atmospheric CO2 levels, coupled with a more recent permanent shortage in water supply as well as high temperatures. Species that use water more efficiently had a selective advantage and were able to spread out into arid habitats.[5]

Taxonomy

[edit]
Cladogram of Amaranthaceae s.l., modified and simplified, based on phylogenetic research of Müller & Borsch 2005, Kadereit et al. 2006, Sanchez del-Pino et al. 2009

In the APG IV system of 2016, as in the previous Angiosperm Phylogeny Group classifications, the family is placed in the order Caryophyllales and includes the plants formerly treated as the family Chenopodiaceae.[6] The monophyly of this broadly defined Amaranthaceae has been strongly supported by both morphological and phylogenetic analyses.[7]

The family Amaranthaceae was first published in 1789 by Antoine Laurent de Jussieu in Genera Plantarum, p. 87–88. The first publication of family Chenopodiaceae was in 1799 by Étienne Pierre Ventenat in Tableau du Regne Vegetal, 2, p. 253. The older name has priority and is now the valid scientific name of the extended Amaranthaceae (s.l. = sensu lato).

Some publications still continued to use the family name Chenopodiaceae.[8][9][10][11][12][13] Phylogenetic research revealed the important impact of the subfamily Polycnemoideae on the classification (see cladogram): if Polycnemoideae are considered a part of Chenopodiaceae, then Amaranthaceae sensu stricto have to be included, too, and the name of the extended family is Amaranthaceae. If Polycnemoideae is separated as its own family, Chenopodiaceae and Amaranthaceae sensu stricto would form two distinct monophyletic groups and could be treated as two separate families.

Amaranthaceae Juss. sensu lato includes the former families Achyranthaceae Raf., Atriplicaceae Durande, Betaceae Burnett, Blitaceae T.Post & Kuntze, Celosiaceae Martynov, Chenopodiaceae Vent. nom. cons., Corispermaceae Link, Deeringiaceae J.Agardh, Dysphaniaceae (Pax) Pax nom. cons., Gomphrenaceae Raf., Polycnemaceae Menge, Salicorniaceae Martynov, Salsolaceae Menge, and Spinaciaceae Menge.

The systematics of Amaranthaceae are the subject of intensive recent research. Molecular genetic studies revealed the traditional classification, based on morphological and anatomical characters, often did not reflect the phylogenetic relationships.

The former Amaranthaceae (in their narrow circumscription) are classified into two subfamilies, Amaranthoideae and Gomphrenoideae, and contain about 65 genera and 900 species in tropical Africa and North America. The Amaranthoideae and some genera of Gomphrenoideae were found to be polyphyletic, so taxonomic changes are needed.[14]

Current studies classified the species of former Chenopodiaceae to eight distinct subfamilies (the research is not yet completed): Polycnemoideae,[4][15] which are sister to the remaining subfamilies; Betoideae;[9] Camphorosmoideae;[13] Chenopodioideae;[12] Corispermoideae;[16] Salicornioideae;[10] Salsoloideae;[8] and Suaedoideae.[17] In this preliminary classification, the Amaranthaceae sensu lato are divided into 10 subfamilies with approximately 180 genera and 2,500 species.[4]

Genera

[edit]

183 genera are accepted.[18] A short synoptic list of genera is given here. For further and more detailed information, see the subfamily pages.

Subfamily Genera
Amaranthoideae Achyranthes, Aerva, Allmania, Allmaniopsis, Amaranthus, Arthraerua, Bosea, Calicorema, Celosia, Centema, Centemopsis, Centrostachys, Chamissoa, Charpentiera, Chionothrix, Cyathula, Dasysphaera, Deeringia, Digera, Eriostylos, Evelynastra, Henonia, Herbstia, Hermbstaedtia, Indobanalia, Kyphocarpa, Lagrezia, Lecosia, Leucosphaera, Lopriorea, Marcelliopsis, Mechowia, Neocentema, Nothosaerva, Nototrichium, Nyssanthes, Omegandra, Ouret, Pandiaka, Paraerva, Pleuropetalum, Pleuropterantha, Polyrhabda, Psilotrichopsis, Psilotrichum, Ptilotus, Pupalia, Rosifax, Saltia, Sebsebea, Sericocoma, Sericorema, Sericostachys, Siamosia, Stilbanthus, Trichuriella, Volkensinia, Wadithamnus
Gomphrenoideae Alternanthera, Froelichia, Froelichiella, Gomphrena, Guilleminea, Hebanthe, Hebanthodes, Iresine, Pedersenia, Pfaffia, Pseudoplantago, Quaternella, Tidestromia, Xerosiphon
Betoideae Acroglochin, Aphanisma, Beta, Hablitzia, Oreobliton, Patellifolia
Camphorosmoideae Bassia, Camphorosma, Chenolea, Didymanthus, Dissocarpus, Enchylaena, Eokochia, Eremophea, Eriochiton, Grubovia, Maireana, Malacocera, Neobassia, Neokochia, Osteocarpum, Roycea, Sclerolaena, Spirobassia, Threlkeldia
Chenopodioideae Archiatriplex, Atriplex, Axyris, Baolia, Blitum, Ceratocarpus, Chenopodiastrum, Chenopodium, Dysphania, Exomis, Extriplex, Grayia, Halimione, Holmbergia, Krascheninnikovia, Lipandra, × Lipastrum, Manochlamys, Microgynoecium, Micromonolepis, Neomonolepis, Oxybasis, Proatriplex, Spinacia, Stutzia, Suckleya, Teloxys
Corispermoideae Agriophyllum, Anthochlamys, Corispermum
Polycnemoideae Hemichroa, Nitrophila, Polycnemum, Surreya
Salicornioideae Allenrolfea, Arthrocaulon (split from Arthrocnemum),[19] Arthroceras (split from Arthrocnemum),[19] Halocnemum, Halopeplis, Halostachys, Heterostachys, Kalidium, Mangleticornia, Microcnemum, Salicornia, Tecticornia
Salsoloideae Afrosalsola, Agathophora, Akhania, Anabasis, Arthrophytum, Caroxylon, Climacoptera, Cornulaca, Cyathobasis, Fadenia, Girgensohnia, Halanthium, Halarchon, Halimocnemis, Halocharis, Halogeton, Halothamnus, Haloxylon, Hammada, Horaninovia, Iljinia, Kaviria, Lagenantha, Nanophyton, Noaea, Nucularia, Ofaiston, Oreosalsola, Petrosimonia, Piptoptera, Pyankovia, Rhaphidophyton, Salsola, Sevada, Soda, Sympegma, Traganopsis, Traganum, Turania, Xylosalsola
Suaedoideae Bienertia, Suaeda

Distribution and habitat

[edit]

Amaranthaceae is a widespread and cosmopolitan family from the tropics to cool temperate regions. The Amaranthaceae (sensu stricto) are predominantly tropical, whereas the former Chenopodiaceae have their centers of diversity in dry temperate and warm temperate areas.[4] Many of the species are halophytes, tolerating salty soils, or grow in dry steppes or semi-deserts.

Uses

[edit]

Some species, such as spinach (Spinacia oleracea) or forms of beet (Beta vulgaris) (beetroot, chard), are used as vegetables. Forms of Beta vulgaris include fodder beet (Mangelwurzel) and sugar beet. The seeds of Amaranthus, lamb's quarters (Chenopodium berlandieri), quinoa (Chenopodium quinoa) and kañiwa (Chenopodium pallidicaule) are edible and are used as pseudocereals.

Dysphania ambrosioides (epazote) and Dysphania anthelmintica are used as medicinal herbs. Several amaranth species are also used indirectly as a source of soda ash, such as members of the genus Salicornia (see glasswort).

A number of species are popular garden ornamental plants, especially species from the genera Alternanthera, Amaranthus, Celosia, and Iresine. Other species are considered weeds, e.g., redroot pigweed (Amaranthus retroflexus) and alligatorweed (Alternanthera philoxeroides), and several are problematic invasive species, particularly in North America, including Salsola tragus and Bassia scoparia. Many species are known to cause pollen allergies.[20]

References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Amaranthaceae

View on Grokipedia
from Grokipedia
Amaranthaceae is a family of flowering plants in the order Caryophyllales, encompassing about 175 genera and more than 2,000 species of mostly herbaceous plants, including annuals, perennials, shrubs, vines, and rarely trees, that are distributed worldwide with a concentration in tropical, subtropical, and arid regions. In modern taxonomy, the family is circumscribed broadly to include the former family Chenopodiaceae, based on molecular phylogenetic evidence that supports their merger, resulting in two main subfamilies: Amaranthoideae and Chenopodioideae. Plants in this family typically feature simple, alternate or opposite leaves that are often succulent or reduced in size, adapted to saline, alkaline, or dry environments, and they produce small, inconspicuous flowers with 3–5 tepals, a superior ovary, and betalain pigments instead of anthocyanins. Many species exhibit C4 or CAM photosynthesis, enabling efficient water use in hot, arid habitats, and their fruits are usually dry utricles containing lenticular or rounded seeds. Economically, Amaranthaceae includes important crops such as grain amaranths (Amaranthus spp.) for pseudocereals, quinoa (Chenopodium quinoa), beets (Beta vulgaris), and spinach (Spinacia oleracea), alongside ornamental plants like cockscomb (Celosia) and various weeds or medicinal species. The family's diversity and adaptability highlight its ecological significance in disturbed soils and its role in human agriculture and cuisine across cultures.

Overview

General characteristics

The Amaranthaceae consists of flowering in the order , encompassing approximately 165 genera and over 2,050 species worldwide. This diverse lineage, which incorporates the former family Chenopodiaceae following modern phylogenetic classifications, exhibits a with centers of diversity in tropical, subtropical, and arid regions. Members are predominantly herbaceous, including annuals and short-lived perennials that account for the majority of species, alongside shrubs, subshrubs, and rarely small trees or vines. A key distinguishing feature of Amaranthaceae is the presence of pigments, which produce characteristic to yellow coloration in flowers, fruits, and vegetative parts, replacing the anthocyanins found in most other angiosperms. Leaves are simple, typically alternate or in , with entire to crenate margins, and lack stipules. Flowers are generally small and inconspicuous, often bisexual or unisexual, and aggregated into dense inflorescences such as , panicles, or glomerules, facilitating wind or insect . Many Amaranthaceae species are adapted as weedy or ruderal plants, thriving in disturbed, arid, saline, or alkaline soils, which contributes to their success as opportunists in human-modified landscapes. Notable examples include invasive weeds like various Amaranthus species, while others serve as important crop plants, such as grain amaranths (Amaranthus spp.) for seeds and greens, beets (Beta vulgaris), and spinach (Spinacia oleracea). This ecological versatility underscores the family's role in both agricultural and natural ecosystems.

Etymology and history

The name Amaranthaceae derives from the genus Amaranthus, its , which in turn originates from word amarantos (ἀμάραντος), meaning "unfading" or "unwithering," in reference to the persistent, colorful bracts that remain vibrant even after the flowers have dried in species such as love-lies-bleeding (Amaranthus caudatus). The genus Amaranthus was first formally described by in his in 1753, where he included several species based on observations of their erect stems, alternate leaves, and clustered inflorescences, establishing foundational documentation for what would become the core of the family. The family Amaranthaceae itself was established by in his Genera Plantarum in 1789, marking its initial recognition as a distinct group within the flowering plants, characterized by features such as small, inconspicuous flowers and dry, one-seeded fruits. Historically, Amaranthaceae was treated as separate from the closely related Chenopodiaceae, which was described shortly after in 1799, though the two families were often allied due to shared traits like succulent leaves and betalain pigments; however, 20th-century studies using molecular data from chloroplast genes like rbcL and pigment analyses confirmed their monophyletic yet distinct clades within Caryophyllales, justifying their separation until further evidence emerged. A key milestone came in the 1960s with the recognition of C4 photosynthesis in many Amaranthaceae species, such as Amaranthus and Gomphrena, where initial CO2 fixation occurs via phosphoenolpyruvate carboxylase in mesophyll cells, enhancing efficiency in hot, arid environments and distinguishing these plants biochemically from C3-dominant families. Phylogenetic analyses supported by the (APG), starting with APG III in 2009 and confirmed in APG IV in 2016—the merger was first proposed in the (APG) I classification in , made optional in APG II (2003), and formalized in APG III (2009), with APG IV (2016) confirming the broad circumscription—led to the merger of Chenopodiaceae into Amaranthaceae sensu lato, reflecting their sister-group relationship and shared evolutionary innovations like betalains and C4 pathways, resulting in a broadened family encompassing about 165 genera.

Description

Morphology

Amaranthaceae exhibit diverse vegetative forms, ranging from or to shrubs, subshrubs, or occasionally small trees, with stems that are simple or branched, terete, striate, or angled, and typically glabrous or pubescent. Stems are predominantly herbaceous but can be woody in certain genera, reaching diameters of 1-10 cm and lengths up to 15 m, often featuring successive rings of interxylary and swollen nodes in opposite-leaved taxa. Leaves are simple, exstipulate, and arranged alternately or oppositely, with blades that are petiolate or sessile, entire or occasionally sinuate-dentate, and pinnately veined with a prominent midvein; margins are typically entire but may be crenate in some species. Inflorescences in Amaranthaceae are composed of cymules arranged in , panicles, thyrses, heads, glomerules, clusters, or racemes, often axillary or terminal and ascending. Bracts and bracteoles subtending each flower are herbaceous or scarious, sometimes spine-tipped, and persistent, with certain genera like featuring colorful, membranous to coriaceous bracts that enhance visual appeal. Flowers are small, actinomorphic, and hypogynous, either bisexual or unisexual (with plants monoecious or dioecious), measuring less than 5 mm in many cases. The perianth consists of (1-)4-5 distinct or connate tepals that are scarious to indurate, free or forming cups or tubes, and typically light green, cream, or whitish. Stamens number 2-5 (rarely up to 8), opposite the tepals, with filaments basally connate into a tube and anthers that are 2- or 4-locular and longitudinally dehiscent. The superior is 1-locular with 1 or rarely 2-many ovules, basal , a single style (or absent), and 1-3(-5) stigmas. Fruits are dry utricles that are dehiscent or indehiscent, often circumscissile, thin-walled or fleshy, and 1- to several-seeded, sometimes persisting in axils. Seeds are small, lenticular, subglobose, or reniform, typically black, reddish-brown, or brown, with a peripheral surrounding abundant mealy perisperm for storage. Morphological variations include succulent habits in halophytic genera such as , where plants are small annual herbs with prostrate to erect, hairless, jointed stems that appear segmented due to reduced internodes, and leaves reduced to minute, opposite, scale-like structures. These succulent forms, often leafless and fleshy, adapt to saline environments through water-storing tissues in the stems.

Anatomy and physiology

The anatomy of Amaranthaceae is adapted to diverse environments, particularly in leaves and stems of C4 photosynthesizing taxa, which often exhibit Kranz anatomy. This specialized structure features vascular bundles surrounded by a wreath-like layer of bundle sheath cells, which are in turn encircled by mesophyll cells, facilitating efficient CO₂ concentration for . In stems, vascular bundles are typically arranged in a collateral pattern, with external to , supporting rapid transport in herbaceous or semi-woody growth forms common to the family. A significant physiological hallmark of many Amaranthaceae species is the pathway, which has arisen independently more than 15 times within the family, enhancing and use efficiency in hot, arid conditions. For instance, in the genus Amaranthus, the NADP-malic enzyme (NADP-ME) subtype predominates, where CO₂ is initially fixed in mesophyll cells by to form four-carbon acids, which are then transported to bundle sheath cells for and entry into the . This process can be summarized as: 4CO2+4H2O+light→2C4 acids→bundle sheath for Calvin cycle4\mathrm{CO_2} + 4\mathrm{H_2O} + \mathrm{light} \rightarrow 2\mathrm{C_4\ acids} \rightarrow \mathrm{bundle\ sheath\ for\ Calvin\ cycle} The pathway minimizes photorespiration, allowing species like Amaranthus hypochondriacus to thrive in high-light, low-water environments. Root systems in Amaranthaceae vary by habitat but generally consist of a primary taproot with extensive fibrous laterals, enabling deep soil penetration for water access in drought-prone areas. In halophytic genera such as Atriplex, roots often develop salt-excreting glands or bladders on the surface to manage ion uptake, preventing toxicity while maintaining osmotic balance in saline soils. Chromosome numbers reflect the family's evolutionary complexity, with a base haploid number of x = 8 or 9 across genera; polyploidy is widespread, as seen in Amaranthus species (2n = 32–34, tetraploid origin) and Beta vulgaris (sugar beet, 2n = 18, diploid). Water relations in Amaranthaceae are supported by succulence in arid-adapted species, particularly in subfamilies like Salicornioideae, where enlarged, water-storing cells in leaves and stems buffer against . Some succulent members also exhibit CAM-like traits or combined C4-CAM , opening stomata nocturnally to reduce while storing CO₂ as malic for daytime use. These adaptations enhance survival in xeric habitats without compromising growth.

Phytochemistry

Amaranthaceae species are characterized by the presence of betalains, a class of nitrogen-containing, water-soluble pigments that replace anthocyanins in this family and related . These pigments are responsible for the vibrant red-violet to yellow coloration in flowers, fruits, and vegetative tissues, serving as visual cues in . Betalains are divided into two main groups: betacyanins, which produce red-violet hues, and betaxanthins, which yield yellow to orange tones.30307-6) The biosynthesis of betalains begins with the amino acid , derived from the , which undergoes and oxidation to form dopaquinone and then cyclizes to betalamic , the common to all betalains. Subsequent conjugation with cyclo-dihydroxyphenylalanine (cyclo-DOPA) yields betacyanins, while reactions with amines or produce betaxanthins; this pathway involves key enzymes such as the monooxygenase CYP76AD1 and a tyrosinase-like activity.30307-6) In addition to betalains, Amaranthaceae accumulate various secondary metabolites, including high levels of oxalic acid, particularly in the leaves of genera like Spinacia (e.g., spinach) and Amaranthus, where soluble and insoluble forms can reach concentrations of 59–131 mg/100 g fresh weight in roots and up to 91 g/kg dry weight in leaves. Other notable compounds include saponins and triterpenoid saponins in species such as Celosia argentea, flavonoids and phenolic acids across multiple genera like Amaranthus and Chenopodium, and alkaloids in ethnomedicinal plants like Aerva lanata. These chemicals play significant ecological roles; betalains provide protection against ultraviolet radiation through light absorption and facilitate pollinator attraction by enhancing floral visibility, while also aiding via frugivores. Oxalates contribute to herbivore defense by forming indigestible crystals that deter chewing and reduce nutrient availability to grazers.30307-6) From a nutritional perspective, betalains exhibit strong activity, scavenging free radicals more effectively than some synthetic antioxidants, with betacyanins showing higher potency than betaxanthins . Unlike many other plant families, Amaranthaceae lack or other alkaloids, emphasizing their role as sources of non-caffeinated, antioxidant-rich greens.

Taxonomy and phylogeny

Classification

Amaranthaceae is classified within the order , belonging to the core clade in the angiosperm phylogeny, and the IV ( of 2016 formally incorporates the former family Chenopodiaceae into Amaranthaceae sensu lato, recognizing their close phylogenetic relationship supported by molecular evidence. This merger reflects extensive phylogenetic analyses that demonstrate the of the combined group, resolving earlier separations based on morphological differences such as bracteole presence and seed coat . The family is subdivided into multiple subfamilies primarily informed by molecular data, including Amaranthoideae, , and Polycnemoideae, with additional lineages such as , Gomphrenoideae, Salicornioideae, and Salsoloideae recognized in recent phylogenomic studies. These divisions highlight evolutionary divergences within the family, where encompasses many former Chenopodiaceae genera, while Amaranthoideae includes core lineages distinguished by pseudostaminodes in flowers. Polycnemoideae, often treated as a basal subfamily, bridges amaranth and chenopod groups through shared traits like simple perianths. Classification relies on a of morphological and molecular diagnostic traits, notably the presence of pigments—nitrogen-containing compounds that produce red to yellow coloration and replace anthocyanins in most families—as a synapomorphy for the . morphology, typically consisting of 1–5 free or connate tepals that may be persistent or , further aids delimitation, varying from colorful and petaloid in ornamental genera to reduced and scale-like in halophytic taxa. Molecular markers, such as chloroplast rbcL gene sequences, have been instrumental in reconstructing phylogenies and confirming subfamily boundaries, with analyses showing high sequence divergence in photosynthetic genes linked to C4 evolution. Amaranthaceae encompasses approximately 180 genera and 2,050–2,500 species worldwide, with the post-2010 taxonomic revisions following the proposed merger adding roughly 500 species from the integrated Chenopodiaceae, enhancing the family's diversity in arid and saline habitats. This expanded circumscription has stabilized the , though ongoing phylogenomic work continues to refine generic limits within subfamilies like .

Genera and species

The Amaranthaceae family encompasses approximately 180 genera and 2,500 , predominantly herbaceous plants with a , though centers of diversity occur in arid, saline, and tropical regions. Among the most prominent genera is Amaranthus, which includes over 90 accepted , many of which are herbs adapted to disturbed habitats; notable examples include A. cruentus, a cultivated for its nutrient-rich seeds. The Beta comprises about 10 , primarily herbs native to and , with B. vulgaris representing the cultivated beet group used for roots, leaves, and sugar production. Chenopodium, a diverse of around 132 , features and goosefoots that thrive in temperate and subtropical zones, often as weeds or crops. Spinacia is smaller, with 3 of leafy s, including the widely grown S. oleracea (). Species diversity within Amaranthaceae is unevenly distributed across subfamilies, with the highest concentrations in the Amaranthoideae and Gomphrenoideae subfamilies, which include tropical and subtropical herbs from genera like Amaranthus and Celosia, accounting for roughly 900 species of the family in warmer regions. In contrast, Chenopodioideae dominates temperate zones with about 100 genera and 1,700 species, encompassing salt-tolerant shrubs and herbs such as those in Atriplex and Salsola. Several species stand out for their ecological or agricultural roles, including Chenopodium quinoa (quinoa), an Andean pseudocereal with saponin-coated seeds valued for protein content, and various Salicornia species (glassworts), succulent halophytes comprising about 35 taxa that accumulate salt in coastal and inland saline environments. Endemism is pronounced in arid regions, particularly Australia, where the genus Maireana (bluebushes) includes 58 species of drought-adapted shrubs restricted to that continent, contributing significantly to the family's diversity in semi-desert ecosystems.

Evolutionary history

The Amaranthaceae family, part of the core order, has a stem lineage divergence estimated at approximately 69.8 million years ago (Mya) during the period, with a crown age around 62.6 Mya at the Cretaceous-Paleogene (K-Pg) boundary. This places the family's origins within the broader diversification of , which exhibit a stem age of about 122 Mya, reflecting early angiosperm radiation. Molecular dating suggests the initial split between Amaranthaceae sensu stricto and the former Chenopodiaceae (now included in Amaranthaceae sensu lato) occurred shortly after, around 61.3 Mya in the early . Fossil evidence supports this timeline, with the oldest known attributable to the Amaranthaceae/Chenopodiaceae alliance being Polyporina cribraria from upper deposits approximately 66 Mya in , indicating early presence near the K-Pg boundary. Additional pollen records from the (35–23 Mya), such as Salicornites massalongoi, and a lower seed (Parvangula randeckensis, ~23.3 Mya) further document the family's persistence and diversification into saline and arid-adapted forms. and stem fossils resembling Chenopodieae, including Salicornia-like systems, appear in sediments from (35.4–23.3 Mya), highlighting adaptations in herbaceous lineages. Major diversification events followed the K-Pg mass extinction, with rapid cladogenesis in the early driven by post-boundary ecological opportunities and subsequent climatic shifts. A significant radiation occurred during the (~20 Mya), particularly in arid and semi-arid environments, coinciding with and the expansion of open habitats, as evidenced by increased lineage splits in lineages like Camphorosmeae in . This burst is linked to adaptations such as C4 photosynthesis, which evolved independently at least three times within the family, enhancing survival in low-CO2, dry conditions. Molecular phylogenies, constructed using nuclear ribosomal ITS and chloroplast matK sequences, robustly support the of Amaranthaceae sensu lato and delineate major clades, including the traditional Chenopodiaceae as sister to Amaranthaceae sensu stricto. These analyses reveal in genera like and highlight adaptive evolution in genes related to stress response. A key biochemical shift was the loss of the pigmentation pathway around 65 Mya, coinciding with the crown age, where betalains replaced anthocyanins as the primary pigments in lineages, driven by mutations in genes and conferring advantages in arid environments.

Distribution and ecology

Geographic range

The Amaranthaceae family exhibits a broad native distribution spanning and temperate regions worldwide, with centers of highest diversity concentrated in the , south of the , and . In the , particularly southwestern , Central and , the family achieves remarkable , exemplified by the Andean region where Chenopodium quinoa () originates as a key adapted to high-altitude environments. African diversity is prominent in arid and semi-arid zones, while Australian taxa contribute significantly to the family's global variation, often in dry continental interiors. Many Amaranthaceae species have been introduced beyond their native ranges, becoming widespread and often invasive weeds, particularly in and . Genera like Amaranthus (pigweeds) are notorious agricultural pests in these regions, spreading through human-mediated trade, cultivation, and transport of contaminated seeds, resulting in a cosmopolitan presence across all continents except . For instance, and related species have naturalized extensively in European croplands and Asian disturbed sites, demonstrating the family's adaptability to anthropogenic landscapes. Biogeographic patterns within the family reveal subfamily-specific distributions: Chenopodioideae species occur worldwide, frequently dominating saline or xeric soils in coastal, , and alkaline habitats from temperate to tropical zones. In contrast, Amaranthoideae taxa are more restricted to dry tropical and subtropical areas, with strong representation in the , , and , reflecting adaptations to warm, arid conditions. Endemism hotspots underscore regional evolutionary uniqueness, with significant concentrations in and southwestern . These areas harbor specialized lineages tied to local edaphic conditions, contributing to the family's overall biogeographic complexity, including diverse genera like Ptilotus in and various chenopods in southern African floras.

Habitats and adaptations

Amaranthaceae species predominantly occupy disturbed soils, salt marshes, deserts, and wetlands, with many exhibiting ruderal or halophytic lifestyles that enable colonization of harsh, human-modified, or naturally stressed environments. Ruderal species, such as those in the genus Amaranthus, thrive in disturbed habitats like roadsides, agricultural fields, and urban areas, where they rapidly establish on nutrient-poor, compacted soils following human activity. Halophytic members, including genera like Suaeda and Salicornia, are common in salt marshes and coastal wetlands, tolerating periodic inundation and high evaporation rates, while desert-adapted taxa such as Salsola dominate arid sandy or rocky terrains. These habitat preferences reflect the family's overall affinity for open, unstable substrates rather than closed-canopy ecosystems. Key physiological adaptations allow Amaranthaceae to endure abiotic stresses, particularly and . Salt tolerance is achieved through ion compartmentation, where excess sodium ions (Na⁺) are sequestered in tissues or vacuoles to prevent cytoplasmic , maintaining homeostasis and osmotic balance; for instance, Amaranthus species accumulate Na⁺ primarily in roots, exhibiting excluder behavior under saline conditions up to 300 mM NaCl. resistance is facilitated by succulence in leaves and stems, reducing water loss, and by C4 in many lineages, which enhances carbon fixation efficiency in hot, dry conditions with minimal . These traits, evolved multiple times within the , underscore adaptations to water-scarce environments. The family favors tropical to arid temperate climates, excelling in warm, seasonal environments like grasslands and savannas with high light intensity and fluctuating , but is underrepresented in humid forests due to shade intolerance and from woody species. Soil requirements often include alkaline or saline conditions, with many taxa, such as , performing well in pH ranges of 7-9 where sodium and levels are elevated, supported by their ability to adjust ion uptake and exclude harmful salts.

Ecological interactions

Members of the Amaranthaceae family predominantly exhibit anemophily, with wind serving as the primary pollination vector due to the production of lightweight, abundant pollen grains adapted for aerial dispersal. However, certain species, such as those in the genera Celosia and Gomphrena, feature colorful bracts that attract insect pollinators, including bees, facilitating entomophily through nectar rewards and visual cues. Amaranthaceae species often face herbivory from chewing and grazers, but they employ chemical defenses, notably high levels of crystals in leaves and stems, which deter consumption by causing or reducing absorption in herbivores. Seed dispersal in the family typically occurs via wind, which carries small, lightweight utricles over short to moderate distances, or through zoochory, where seeds adhere to or pass through digestive tracts unharmed. In ecosystems, Amaranthaceae plants contribute to , particularly in coastal dunes, where species like Amaranthus pumilus act as effective sand binders by anchoring shifting substrates with their extensive root systems. Some taxa form symbiotic associations with nitrogen-fixing bacteria, such as species, in their root zones, enhancing plant growth and nitrogen availability in nutrient-poor soils. Additionally, certain species, including , demonstrate invasive potential in grasslands and disturbed areas, rapidly colonizing open habitats and outcompeting native vegetation through prolific seed production and tolerance to environmental stresses. Mycorrhizal associations are rare in Amaranthaceae, with many species, particularly in the Amaranthus genus, classified as non-mycorrhizal or showing only occasional colonization by arbuscular mycorrhizal fungi, likely due to adaptations for nutrient uptake in saline or arid environments.

Economic and cultural significance

Culinary and medicinal uses

Plants in the Amaranthaceae family have been integral to human diets for millennia, with several species domesticated for their edible grains, leaves, and stems. Amaranthus species, such as A. hypochondriacus and A. cruentus, produce grains used in porridges, breads, and flours, while quinoa provides nutrient-dense seeds cooked as a staple grain in Andean . Leaves of Spinacia oleracea (spinach) and (beets) are consumed fresh in salads or cooked as greens, valued for their mild flavor and versatility in soups and stir-fries. Stems of species, known as sea beans or , are harvested for their crisp texture and natural salinity, often featured in salads or as a garnish in coastal cuisines. has a long history of cultivation dating back to ancient times in the Mediterranean and , initially for its leafy greens. The nutritional profile of Amaranthaceae grains and highlights their role as gluten-free alternatives to traditional cereals, offering high-quality protein and essential micronutrients. and grains contain 14-18% protein, significantly higher than many cereals, with a balanced composition rich in , an often limiting in staples like . These pseudocereals are also abundant in (up to 7-10 g/100 g), iron (2-5 mg/100 g in leaves and grains), and other minerals, supporting digestive health and preventing deficiencies in plant-based diets. leaves and beet greens further contribute vitamins A and C, enhancing their value as nutrient-dense . Medicinally, Amaranthaceae plants are employed for their bioactive compounds, particularly betalains, which exhibit properties by scavenging free radicals and modulating inflammatory pathways. () has been traditionally used to alleviate due to its high iron content and , aiding production in folk remedies across and . Amaranth leaves and seeds are brewed into teas for digestive support, with studies indicating their and content help soothe gastrointestinal issues like ulcers. These applications underscore the family's therapeutic potential, though high levels in some leaves may require moderation in consumption for individuals prone to kidney stones.

Ornamental and industrial applications

Members of the Amaranthaceae family, particularly species in the genus Celosia, are widely cultivated as ornamental plants for their vibrant, long-lasting inflorescences that add color to gardens and landscapes. Celosia argentea var. cristata, commonly known as cockscomb, features velvety, fan-like flower heads in shades of red, pink, orange, and yellow, which are prized for their unique texture and ability to create focal points in bedding displays, borders, or containers. These plants thrive in full sun and well-drained soils, blooming continuously from summer to fall, making them popular annuals in temperate regions. In , inflorescences serve as excellent due to their durability, with fresh blooms lasting 5 to 14 days in vases and dried specimens retaining color and shape for extended periods in arrangements. The persistent bracts and plume- or crested-shaped heads of Celosia species provide textural variety in bouquets, boutonnieres, and centerpieces, often used to evoke warmth and whimsy. Similarly, Amaranthus species, such as love-lies-bleeding (A. caudatus), are employed in dried flower crafts for their cascading, colorful tassels that maintain vibrancy without fading. Betalains, the characteristic pigments of Amaranthaceae, find significant industrial application as colorants, offering hues as an alternative to synthetic dyes. , extracted primarily from (red beetroot), is approved as E162 in the and used to color products like yogurts, ice creams, jams, sauces, and beverages, where it provides stability in low-pH and frozen conditions. Other Amaranthaceae sources, including Amaranthus and , contribute betacyanins like amaranthin for similar applications in and , valued for their properties alongside coloring. Stems of certain Amaranthaceae species, such as Amaranthus hybrids, yield cellulosic fibers suitable for industrial uses in textiles and paper production. In regions like , these bast fibers are extracted via and processed into yarns, ropes, bags, and mats, serving as a sustainable alternative or blend to . Amaranthus hybridus stalks, in particular, produce pulp with promising properties for when treated with soda pulping, demonstrating potential in low-cost fiber industries. Biomass from Amaranthaceae, notably Amaranthus species, is explored for production due to high yields and lignocellulosic content. Dry matter content averages 15.5% with plant heights up to 330 cm across accessions, enabling energy-rich feedstocks for bioethanol or via of stems and leaves. For instance, Amaranthus hybridus waste can be briquetted with binders like starch to form solid biofuels, optimizing combustion efficiency. Sugar beet pulp (Beta vulgaris subsp. vulgaris), a of sugar extraction, is a key resource for animal fodder, providing digestible and to . Comprising about 50% and 15-18% pectins on a basis, wet or pressed pulp is fed to ruminants at up to 40% of the diet, supporting dairy cow milk production and growth without digestive issues. Its high calcium content and palatability make it suitable for pigs and horses as well, often ensiled for year-round use. Red pigments from Amaranthaceae have been used as dyes since ancient times, particularly by Native American communities. The people extract magenta dye from the bracts of 'Hopi Red Dye' by soaking them in water, applying it to color dough for ceremonial bread or textiles with mordants for colorfastness. Pueblo peoples similarly employ wild amaranths growing near fields to produce red hues for (fermented beverage) and fabrics, a practice documented in ethnobotanical records. Modern biotechnological advances include genetic engineering to produce betalains in bacteria, expanding sustainable pigment sources beyond plants. Researchers have engineered Escherichia coli with genes like DODA (4,5-DOPA dioxygenase) from betalain-producing bacteria, enabling de novo synthesis of betaxanthins and betacyanins for scalable food colorant production. This microbial approach circumvents plant extraction limitations, achieving titers suitable for industrial fermentation.

Conservation status

The Amaranthaceae family encompasses a diverse array of , many of which face varying degrees of conservation concern, though the majority remain unevaluated or of least concern on the . Only a small fraction are classified as threatened. Notable examples include Beta patula, a critically endangered endemic to the Madeira Archipelago, threatened by habitat degradation and , and Amaranthus brownii, also critically endangered and federally listed due to its restricted range on the Hawaiian island of Nihoa. In 2025, Amaranthus pakai was newly described and assessed as critically endangered, last observed in the wild in 2014 and restricted to the . In contrast, widespread weedy such as are categorized as least concern but contribute to ecological disruptions as invasive plants in non-native regions. Primary threats to Amaranthaceae include habitat loss in and coastal environments, driven by agricultural expansion, , and drainage for development, which disproportionately affects salt-tolerant halophytes and riparian taxa. Overharvesting of wild relatives of cultivated , such as those related to (Chenopodium quinoa) in the Andean highlands, exacerbates and population declines, as these plants are collected for , , and breeding stock amid increasing demand. Additionally, the invasiveness of weedy members like Amaranthus retroflexus poses indirect threats by outcompeting native vegetation in disturbed habitats across , , and , altering community structures and reducing . Conservation efforts emphasize ex situ strategies, including seed banking for crop wild relatives to preserve essential for breeding resilient varieties. Global repositories hold over 16,000 accessions of and its wild relatives, primarily in and , supporting long-term viability assessments and restoration programs. In situ protection occurs through designated areas in arid hotspots, such as in , which safeguards endemic Amaranthaceae like Arthraerua leubnitziae from and pressures. Climate change amplifies vulnerabilities, particularly for halophytic species in the family, which face heightened salinization from sea-level rise inundating coastal wetlands and salt marshes. This process, projected to increase salinity stress irreversibly in arid zones, threatens taxa like species by disrupting and survival, underscoring the need for in vulnerable ecosystems.

References

  1. https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/amaranthaceae
  2. https://onlinelibrary.wiley.com/doi/full/10.1002/ece3.70013
  3. https://academic.oup.com/botlinnean/article/181/1/1/2416499
  4. https://floranorthamerica.org/Amaranthaceae
  5. https://www.sciencedirect.com/science/article/pii/B9780123743800500087
  6. https://pmc.ncbi.nlm.nih.gov/articles/PMC11201225/
  7. https://pmc.ncbi.nlm.nih.gov/articles/PMC5946119/
  8. https://naturalhistory.si.edu/sites/default/files/media/file/amaranthaceae_0.pdf
  9. https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=46
  10. https://www.journals.uchicago.edu/doi/10.1086/378649
  11. https://www.etymonline.com/word/amaranth
  12. https://mainenaturalhistory.org/Biodiversity_Project/checklistsME/Tracheophyta_tricolpates/Amaranthaceae.htm
  13. http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=101257
  14. https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:30000566-2
  15. https://academic.oup.com/jxb/article/62/9/3155/474202
  16. https://academic.oup.com/annbot/article/103/3/347/2626659
  17. https://pmc.ncbi.nlm.nih.gov/articles/PMC8103812/
  18. https://academic.oup.com/botlinnean/article/172/2/175/2416261
  19. https://pmc.ncbi.nlm.nih.gov/articles/PMC3075750/
  20. https://pmc.ncbi.nlm.nih.gov/articles/PMC8624041/
  21. https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2016.01525/full
  22. https://pmc.ncbi.nlm.nih.gov/articles/PMC4241080/
  23. https://eorganic.org/node/5125
  24. https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.00406/full
  25. https://pubs.aip.org/aip/acp/article-pdf/doi/10.1063/1.5050149/14060160/020053_1_online.pdf
  26. http://inspection.canada.ca/en/plant-varieties/plants-novel-traits/applicants/directive-94-08/biology-documents/beta-vulgaris
  27. https://academic.oup.com/jxb/article/68/9/2121/3084721
  28. https://pmc.ncbi.nlm.nih.gov/articles/PMC10799995/
  29. https://www.sciencedirect.com/science/article/pii/S017616172300175X
  30. https://www.nature.com/articles/s41598-021-85486-x
  31. https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.15980
  32. https://www.sciencedirect.com/science/article/abs/pii/S0308814605004826
  33. https://scijournals.onlinelibrary.wiley.com/doi/10.1002/jsfa.2740480409
  34. https://www.sciencedirect.com/science/article/abs/pii/S0378874118320932
  35. https://onlinelibrary.wiley.com/doi/full/10.1002/cbdv.202403456
  36. https://medcraveonline.com/PPIJ/pharmacognostic-antibacterial-and-anti-oxidantactivity-of-aerva-lanata-l-al-juss-ex-schultes-amaranthaceae.html
  37. https://www.sciencedirect.com/science/article/pii/S1674205217303076
  38. https://www.researchgate.net/publication/6321961_Oxalate_in_Grain_Amaranth
  39. https://pubs.acs.org/doi/10.1021/jf030045u
  40. https://doi.org/10.1111/boj.12385
  41. https://doi.org/10.1002/ece3.70013
  42. https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:327362-2
  43. https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:30253697-2
  44. https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:60437273-2
  45. https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:7004-1
  46. https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:329966-2
  47. https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:6919-1
  48. https://pmc.ncbi.nlm.nih.gov/articles/PMC11246835/
  49. http://brockingtonlab.co.uk/publications/1-s20-s1055790318302252.pdf
  50. https://www.sciencedirect.com/science/article/pii/S1439609205000152
  51. https://www.sciencedirect.com/science/article/pii/S1433831924000349
  52. https://pmc.ncbi.nlm.nih.gov/articles/PMC10952170/
  53. https://onlinelibrary.wiley.com/doi/full/10.1002/ece3.10720
  54. https://cals.cornell.edu/weed-science/weed-profiles/pigweeds
  55. https://seedidguide.idseed.org/fact_sheets/31966/
  56. https://www.sciencedirect.com/science/article/abs/pii/S1040618211005830
  57. https://www.biodiversityexplorer.info/plants/amaranthaceae/index.htm
  58. https://botany.one/2021/03/the-shape-of-baby-plants-in-the-amaranth-family-show-adaptations-to-extreme-habitats/
  59. https://pmc.ncbi.nlm.nih.gov/articles/PMC8877964/
  60. https://doi.org/10.3389/fpls.2021.604481
  61. https://academic.oup.com/aob/article/115/3/327/306278
  62. https://pmc.ncbi.nlm.nih.gov/articles/PMC10405290/
  63. https://www.researchgate.net/publication/348928706_Sexual_systems_pollination_modes_and_fruiting_ecology_of_three_common_herbaceous_weeds_Aerva_lanata_L_Juss_Ex_Schult_Allmania_nodiflora_L_RBr_and_Pupalia_lappacea_L_Juss_Family_Amaranthaceae_Sub-famil
  64. https://plants.ces.ncsu.edu/plants/celosia-argentea/
  65. https://pmc.ncbi.nlm.nih.gov/articles/PMC3146458/
  66. https://www.fws.gov/species/seabeach-amaranth-amaranthus-pumilus
  67. https://www.aphis.usda.gov/sites/default/files/amaranthus-palmeri.pdf
  68. https://my.ucanr.edu/repository/a/?a=167060
  69. https://pmc.ncbi.nlm.nih.gov/articles/PMC6214444/
  70. https://pmc.ncbi.nlm.nih.gov/articles/PMC3922803/
  71. https://www.nwcb.wa.gov/weeds/palmer-amaranth
  72. https://research.fs.usda.gov/feis/species-reviews/amaret
  73. https://researchrepository.wvu.edu/cgi/viewcontent.cgi?article=2029&context=etd
  74. https://pmc.ncbi.nlm.nih.gov/articles/PMC10747716/
  75. https://www.clovegarden.com/ingred/ch_amaranth.html
  76. https://pmc.ncbi.nlm.nih.gov/articles/PMC4835422/
  77. https://onlinelibrary.wiley.com/doi/10.1155/2023/1753029
  78. https://www.intechopen.com/chapters/67741
  79. https://pmc.ncbi.nlm.nih.gov/articles/PMC6987210/
  80. https://www.sciencedirect.com/science/article/pii/S2666149721000086
  81. https://pmc.ncbi.nlm.nih.gov/articles/PMC8871380/
  82. https://ift.onlinelibrary.wiley.com/doi/10.1111/1541-4337.12021
  83. https://plants.ces.ncsu.edu/plants/celosia/
  84. https://extension.msstate.edu/publications/cockscomb-celosia-argentea-var-cristata-for-the-farmer-florist
  85. https://www.researchgate.net/publication/364376836_Stem_Amaranth_Fiber
  86. https://www.phytojournal.com/archives/2017/vol6issue6/PartAC/6-6-224-907.pdf
  87. https://www.researchgate.net/publication/332687050_Amaranth_A_Potential_Source_of_Bioenergy_Biofuel_Crops
  88. https://pmc.ncbi.nlm.nih.gov/articles/PMC11004732/
  89. https://www.feedipedia.org/node/710
  90. https://www.nativeseeds.org/pages/hopi-red-dye-amaranth
  91. https://www.jstor.org/stable/3628567
  92. https://journals.asm.org/doi/10.1128/mbio.00345-19
  93. https://pmc.ncbi.nlm.nih.gov/articles/PMC6681404/
  94. https://novon.mobot.org/index.php/novon/article/view/953
  95. https://dlnr.hawaii.gov/wildlife/files/2013/09/Fact-Sheet-Amaranthus-brownii.pdf
  96. https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.138217/Amaranthus_retroflexus
  97. https://www.apn-gcr.org/wp-content/uploads/2020/09/eb7cd02beca7df787e60676f8c0ebb70.pdf
  98. https://iucn.org/news/species/202109/threats-crop-wild-relatives-compromising-food-security-and-livelihoods
  99. https://onlinelibrary.wiley.com/doi/abs/10.1111/wre.12282
  100. https://www.researchgate.net/publication/274377128_Quinoa_genetic_resources_and_ex_situ_conservation
  101. https://www.frontiersin.org/journals/sustainable-food-systems/articles/10.3389/fsufs.2022.960159/full
  102. https://www.researchgate.net/publication/367859051_Plant_Ecology_of_the_Namib_Desert
  103. https://www.mdpi.com/2673-4060/5/1/3
  104. https://www.sciencedirect.com/science/article/pii/S2468265918301835
Add your contribution
Related Hubs
User Avatar
No comments yet.