''Chenopodium'' is a genus of numerous species of perennial or annual plant, annual herbaceous flowering plants known as the goosefoot, which occur almost anywhere in the world. It is placed in the family Amaranthaceae in the APG II system; older classification systems, notably the widely used Cronquist system, separate it and its relatives as Chenopodiaceae, but this leaves the rest of the Amaranthaceae polyphyletic. However, among the Amaranthaceae, the genus ''Chenopodium'' is the namesake member of the subfamily Chenopodioideae.

Description

The species of ''Chenopodium'' (s.str., description according to Fuentes et al. 2012) are Annual plant, annual or perennial herbs, shrubs or small trees. They generally rely on alkaline soil. They are nonaromatic, but sometimes fetid (foul-smelling). The young stems and leaves are often densely covered by vesicular globose hairs, thus looking Epicuticular wax#Farina, farinose. Characteristically, these trichomes persist, collapsing later and becoming cup-shaped. The branched Plant stem, stems grow erect, ascending, prostrate or scrambling. Lateral branches are alternate (the lowermost ones can be nearly opposite). The alternate or opposite leaves are petiole (botany), petiolate. Their thin or slightly fleshy leaf blade is linear, Rhombus, rhombic or triangular-hastate, with entire (botany), entire or dentate leaf, dentate or lobed margins. Inflorescences are standing botanical terms#terminal, terminal and botanical terms#lateral, lateral. They consist of botanical terms#spicate, spicately or botanical terms#paniculate, paniculately arranged wikt:glomerule , glomerules of flowers. Plants are monoecious (rarely dioecious). In monoecious plants flowers are Sexual dimorphism, dimorphic or pistillate. Flowers consist of (4–) 5 perianth segments Connation, connate, basally (at the base) or close to the middle, usually membranous margined and with a roundish to keeled back; almost always 5 stamens, and one ovary with 2 stigmas. In fruit, perianth segments become sometimes coloured, but mostly keep unchanged, somewhat closing over or spreading from the fruit. The pericarp is membranous or sometimes succulent, adherent to or loosely covering the seed. The horizontally oriented seeds are depressed-globular to lenticular, with rounded to subacute margin. The black seed coat is almost smooth to finely striate, rugulose or pitted.

Taxonomy

The genus ''Chenopodium'' was described by Carl Linnaeus in 1753 (In: ''Species Plantarum'', Vol. 1, p. 218–222). Type species is ''Chenopodium album''. This generic name is derived from the particular shape of the leaf, which is similar to a goose's foot: from Greek language, Greek χήν (''chen''), "goose" and πούς (''pous''), "foot" or (''podion''), "little foot". In its traditional circumscription, ''Chenopodium'' comprised about 170 species. Phylogenetic research revealed, that the genus was highly polyphyletic and did not reflect how species were naturally related. Therefore, a new classification was necessary. Mosyakin & Clemants (2002, 2008) separated the glandular species as genus ''Dysphania (plant), Dysphania'' (which includes epazote) and ''Teloxys'' in tribe Dysphanieae. Fuentes-Bazan et al. (2012) separated many species to genera ''Blitum'' (in tribe Anserineae), ''Chenopodiastrum'', ''Lipandra'', and ''Oxybasis'' (like ''Chenopodium'' in tribe Atripliceae). They included ''Rhagodia'' and ''Einadia'' in ''Chenopodium''.

Species

132 species are currently accepted. * ''Chenopodium acerifolium'' * ''Chenopodium aciculare'' * ''Chenopodium acuminatum'' Willd. * ''Chenopodium adpressifolium'' * ''Chenopodium albescens'' * ''Chenopodium album'' – white goosefoot, nickel greens, dungweed, ''bathua'', ''chandali'', ''chandaliya'', fat hen, lamb's quarters, pigweed ** ''Chenopodium album'' var. ''album'' (synonym ''Chenopodium strictum'' Roth) * ''Chenopodium allanii'' * ''Chenopodium atripliciforme'' * ''Chenopodium atrovirens'' – dark goosefoot, pinyon goosefoot * ''Chenopodium attenuatum'' * ''Chenopodium aureum'' – golden goosefoot * ''Chenopodium auricomiforme'' * ''Chenopodium auricomum'' – Queensland bluebush * ''Chenopodium ayare'' * ''Chenopodium baccatum'' (Syn. ''Rhagodia baccata'') * ''Chenopodium benthamii'' (Syn.: ''Rhagodia latifolia'') * ''Chenopodium berlandieri'' – pitseed goosefoot, southern huauzontle, lambsquarters ** ''Chenopodium berlandieri'' var. ''berlandieri'' (synonym ''Chenopodium nuttalliae'' ) – huauzontle, chia roja, quelit * ''Chenopodium betaceum'' * ''Chenopodium × binzianum'' * ''Chenopodium × bohemicum'' * ''Chenopodium × borbasii'' * ''Chenopodium brandegeeae'' – Brandegee's goosefoot * ''Chenopodium bryoniifolium'' Bunge – Korean goosefoot * ''Chenopodium candolleanum'' (Syn.: ''Rhagodia candolleana'') * ''Chenopodium carnosulum'' * ''Chenopodium chaldoranicum'' * ''Chenopodium cordobense'' * ''Chenopodium cornutum'' * ''Chenopodium × covillei'' * ''Chenopodium crusoeanum'' * ''Chenopodium cuneifolium'' * ''Chenopodium curvispicatum'' * ''Chenopodium cyanifolium'' * ''Chenopodium cycloides'' – sandhill goosefoot * ''Chenopodium × dadakovae'' * ''Chenopodium desertorum'' – desert goosefoot * ''Chenopodium desiccatum'' – narrowleaf goosefoot * ''Chenopodium detestans'' – New Zealand fish-guts plant * ''Chenopodium diversifolium'' * ''Chenopodium drummondii'' (Syn.: ''Rhagodia drummondii'') * ''Chenopodium eastwoodiae'' – Eastwood's goosefoot * ''Chenopodium eremaeum'' (Syn.: ''Rhagodia eremaea'') * ''Chenopodium erosum'' R.Br. * ''Chenopodium eustriatum'' * ''Chenopodium × fallax'' * ''Chenopodium ficifoliiforme'' * ''Chenopodium ficifolium'' – fig-leaved goosefoot, small goosefoot * ''Chenopodium flabellifolium'' – San Martin Island goosefoot, flabelliform goosefoot * ''Chenopodium foggii'' – Fogg's goosefoot * ''Chenopodium fremontii'' – Fremont's goosefoot * ''Chenopodium frutescens'' * ''Chenopodium × fursajevii'' * ''Chenopodium gaudichaudianum'' * ''Chenopodium giganteum'' D.Don (synonym ''Chenopodium formosanum'' ) – tree spinach, red quinoa, djulis * ''Chenopodium griseochlorinum'' * ''Chenopodium grubovii'' * ''Chenopodium × gruellii'' * ''Chenopodium harae'' * ''Chenopodium hastatifolium'' * ''Chenopodium × haywardiae'' * ''Chenopodium hederiforme'' * ''Chenopodium hians'' * ''Chenopodium hircinum'' * ''Chenopodium hoggarense'' * ''Chenopodium howellii'' – Howell's goosefoot * ''Chenopodium hubbardii'' * ''Chenopodium × humiliforme'' * ''Chenopodium iljinii'' * ''Chenopodium incanum'' – mealy goosefoot * ''Chenopodium incognitum'' * ''Chenopodium indicum'' * ''Chenopodium iranicum'' * ''Chenopodium × jedlickae'' * ''Chenopodium × jehlikii'' * ''Chenopodium karoi'' * ''Chenopodium khorasanica'' * ''Chenopodium lenticulare'' * ''Chenopodium × leptophylliforme'' * ''Chenopodium leptophyllum'' – narrowleaf goosefoot * ''Chenopodium × linciense'' * ''Chenopodium lineatum'' – Mono goosefoot * ''Chenopodium littoreum'' – coastal goosefoot * ''Chenopodium lobodontum'' * ''Chenopodium loureiroi'' * ''Chenopodium luteorubrum'' * ''Chenopodium luteum'' – yellow goosefoot * ''Chenopodium × mendelii'' * ''Chenopodium moquinianum'' * ''Chenopodium mucronatum'' * ''Chenopodium neomexicanum'' – New Mexico goosefoot * ''Chenopodium nesodendron'' * ''Chenopodium nevadense'' – Nevada goosefoot * ''Chenopodium nitens'' * ''Chenopodium nitrariaceum'' (F.Muell.) F.Muell. ex Benth. – nitre goosefoot * ''Chenopodium nitens'' – shiny goosefoot * ''Chenopodium novopokrovskyanum'' * ''Chenopodium nutans'' (Syn.: ''Rhagodia nutans'') * ''Chenopodium oahuense'' – ''Āheahea'' (Hawaii, Hawaii) * ''Chenopodium obscurum'' * ''Chenopodium opulifolium'' Schrad. ex W.D.J.Koch & Ziz – grey goosefoot * ''Chenopodium pallescens'' – pallid goosefoot * ''Chenopodium pallidicaule'' – ''kañiwa'', "cañahua" * ''Chenopodium palmeri'' – Palmer's goosefoot * ''Chenopodium pamiricum'' * ''Chenopodium parabolicum'' (Syn.: ''Rhagodia parabolica'') * ''Chenopodium × paradoxum'' * ''Chenopodium parryi'' – Parry's goosefoot * ''Chenopodium perttii'' * ''Chenopodium petiolare'' * ''Chenopodium philippianum'' * ''Chenopodium phillipsianum'' * ''Chenopodium pilcomayense'' * ''Chenopodium × podperae'' * ''Chenopodium polygonoides'' * ''Chenopodium × praeacutum'' * ''Chenopodium pratericola'' Rydb. – pale goosefoot, desert goosefoot, narrowleaf goosefoot * ''Chenopodium preissii'' (Syn. ''Rhagodia preissii'') * ''Chenopodium × preissmannii'' * ''Chenopodium × pseudoleptophyllum'' * ''Chenopodium × pseudostriatum'' * ''Chenopodium pueblense'' * ''Chenopodium quinoa'' – quinoa * ''Chenopodium × reynieri'' * ''Chenopodium robertianum'' (Syn.: ''Rhagodia hastata'') * ''Chenopodium ruiz-lealii'' * ''Chenopodium sanctae-clarae'' * ''Chenopodium sancti-ambrosii'' * ''Chenopodium sandersii'' – Sander's goosefoot * ''Chenopodium santoshei'' * ''Chenopodium scabricaule'' * ''Chenopodium simpsonii'' – Simpson's goosefoot * ''Chenopodium × smardae'' * ''Chenopodium sonorense'' – Sonoran goosefoot * ''Chenopodium sosnowskyi'' * ''Chenopodium spegazzinii'' * ''Chenopodium spinescens'' (Syn. ''Rhagodia spinescens'') * ''Chenopodium standleyanum'' – Standley's goosefoot * ''Chenopodium stenophyllum'' * ''Chenopodium striatiforme'' * ''Chenopodium subficifolium'' * ''Chenopodium subglabrum'' – smooth arid goosefoot, smooth goosefoot * ''Chenopodium suecicum'' – green goosefoot * ''Chenopodium × thellungii'' * ''Chenopodium tonkinense'' * ''Chenopodium triandrum'' (Syn.: ''Rhagodia triandra'') * ''Chenopodium × tridentinum'' * ''Chenopodium × trigonocarpum'' * ''Chenopodium trigonon'' (Syn.: ''Einadia trigonos'') * ''Chenopodium twisselmannii'' – Twisselmann's goosefoot, high meadow goosefoot * ''Chenopodium ulbrichii'' * ''Chenopodium ulicinum'' * ''Chenopodium × unarii'' * ''Chenopodium × variabile'' (''C. album × C. berlandieri'') * ''Chenopodium vulvaria'' – stinking goosefoot, notchweed * ''Chenopodium wahlii'' – Wahl's goosefoot * ''Chenopodium watsonii'' – Watson's goosefoot * ''Chenopodium wilsonii'' (Syn.: ''Rhagodia crassifolia'') * ''Chenopodium × zahnii'' * ''Chenopodium zerovii'' * ''Chenopodium zoellneri''

Excluded species

* ''Blitum'' (12 species): ** ''Blitum bonus-henricus'' – Good King Henry, perennial goosefoot, poor-man's asparagus, Lincolnshire spinach, markery ** ''Blitum californicum'' – California goosefoot, Indian lettuce ** ''Blitum capitatum'' – strawberry blite, blite goosefoot, strawberry goosefoot, strawberry spinach, Indian paint, Indian ink ** ''Blitum virgatum'' (Syn. ''Chenopodium foliosum'') – leafy goosefoot * ''Chenopodiastrum'' (5 species): ** ''Chenopodiastrum murale'' – nettle-leaved goosefoot ** ''Chenopodiastrum simplex'' – giant seed goosefoot * ''Dysphania (plant), Dysphania'' (about 43 glandular species, as ''C. botrys, C. carinatum, C. cristatum, C. melanocarpum, C. multifidium, C. pumilio'' and more) * ''Lipandra'' (one species): ** ''Lipandra polysperma'' – many-seeded goosefoot * ''Oxybasis'' (5 species): ** ''Oxybasis chenopodioides'' – small red goosefoot, saltmarsh goosefoot ** ''Oxybasis glauca'' – oak-leaved goosefoot ** ''Oxybasis rubra'' – red goosefoot, coastblite goosefoot ** ''Oxybasis urbica'' – upright goosefoot * ''Teloxys'' (one species): ** ''Teloxys aristata'' * ''Suaeda australis'' – austral seablite (as ''C. australe, C. insulare'')

Ecology

Certain species grow in large thickets, providing cover for small animals. Goosefoot foliage is used as food by the caterpillars of certain Lepidoptera. The seeds are eaten by many birds, such as the yellowhammer (''Emberiza citrinella'') of Europe or the white-winged fairy-wren (''Malurus leucopterus'') of Australia. Goosefoot plant pathogen, pathogens include the positive-sense ssRNA virusesapple stem grooving virus, sowbane mosaic virus and tobacco necrosis virus.

Uses

The genus ''Chenopodium'' contains several plants of minor to moderate importance as food crops as leaf vegetables – used like the closely related spinach (''Spinacia oleracea'') and similar plants called ''quelite'' in Mexicoand pseudocereals. These include white goosefoot (''C. album''), ''kañiwa'' (''C. pallidicaule'') and quinoa (''C. quinoa''). On the Greece, Greek island of Crete, tender shoots and leaves of a species called ''krouvida'' () or ''psarovlito'' () are eaten by the locals, boiled or steamed. As studied by Bruce D. Smith, Kristen Gremillion and others, goosefoots have a history of culinary use dating back to 4000 BC or earlier, when pitseed goosefoot (''C. berlandieri'') was a staple crop in the Native American Eastern Agricultural Complex, and when white goosefoot was apparently used by the Ertebølle culture of Europe. Members of the eastern European Yamna culture, Yamnaya culture also harvested white goosefoot as an apparent cereal substitute to round out an otherwise mostly meat and dairy diet c.'' ''3500–2500'' ''BC. There is increased interest in particular in goosefoot seeds today, which are suitable as part of a gluten-free diet. Quinoa oil, extracted from the seeds of ''C. quinoa'', has similar properties, but is superior in quality, to corn oil. Oil of chenopodium is extracted from the seeds of epazote, which is not in this genus anymore. Shagreen leather was produced in the past using the small, hard goosefoot seeds. ''C. album'' was one of the main model organisms for the molecular biological study of chlorophyllase. Goosefoot pollen, in particular of the widespread and usually abundant ''C. album'', is an allergen to many people and a common cause of hay fever. The same species, as well as some others, have seeds which are able to persist for years in the soil seed bank. Many goosefoot species are thus significant weeds, and some have become invasive species. In Australia, the larger ''Chenopodium'' species are among the plants called "bluebushes". According to the 1889 book ''The Useful Native Plants of Australia'', ''Chenopodium auricomum'' "is another of the salt-bushes, which, besides being invaluable food for stock, can be eaten by man. All plants of the Natural Order Chenopodiaceae (Salsolacese) are more or less useful in this respect." The book goes on to give the following account from the ''Journal de la Ferme et des Maisons de campagne'':

We have recently gathered an abundant harvest of leaves from two or three plants growing in our garden. These leaves were put into boiling water to blanch them, and they were then cooked as an ordinary dish of spinach, with this difference in favour of the new plant, that there was no occasion to take away the threads which are so disagreeable in chicory, sorrel, and ordinary spinach. We partook of this dish with relish—the flavour—analogous to spinach, had something in it more refined, less grassy in taste. The cultivation is easy: sow the seed in April (October) in a well-manured bed, for the plant is greedy; water it. The leaves may be gathered from the time the plant attains 50 centimetres (say 20 inches) in height. They grow up again quickly. In less than eight days afterwards another gathering may take place, and so on to the end of the year.

Safety

Raphides, Sphaeraphides occur in the leaves, stem, pith and mesophloem.

Fossil record

†''Chenopodium wetzleri'' fossil seeds of the Chattian stage, Oligocene, are known from the Oberleichtersbach Formation in the Rhön Mountains, central Germany.The floral change in the tertiary of the Rhön mountains (Germany) by Dieter Hans Mai - Acta Paleobotanica 47(1): 135-143, 2007.

References

Susy Fuentes-Bazan, Pertti Uotila, Thomas Borsch: ''A novel phylogeny-based generic classification for Chenopodium sensu lato, and a tribal rearrangement of Chenopodioideae (Chenopodiaceae).'' In: ''Willdenowia.'' Vol. 42, No. 1, 2012, p. 5-24. Gelin Zhu, Sergei L. Mosyakin & Steven E. Clemants
''Chenopodium'' - In: Wu Zhengyi, Peter H. Raven, Deyuan Hong (Hrsg.): Flora of China.
Volume 5: Ulmaceae through Basellaceae. Science Press/Missouri Botanical Garden Press, Beijing/St. Louis 2003, , p. 378-.