''Spinacia'' is a flowering plant

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

in the subfamily

Chenopodioideae The Chenopodioideae are a subfamily of the flowering plant family Amaranthaceae in the APG III system, which is largely based on molecular phylogeny, but were included - together with other subfamilies - in family Chenopodiaceae in the Cronqui ...

of the family

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

. The most common member is

spinach Spinach (''Spinacia oleracea'') is a leafy green flowering plant native to central and western Asia. It is of the order Caryophyllales, family Amaranthaceae, subfamily Chenopodioideae. Its leaves are a common edible vegetable consumed either f ...

Description

The species in genus ''Spinacia'' are

annual Annual may refer to: *Annual publication, periodical publications appearing regularly once per year ** Yearbook ** Literary annual *Annual plant *Annual report *Annual giving *Annual, Morocco, a settlement in northeastern Morocco *Annuals (band), ...

or biennial herbs. Plants are always glabrous. Their stems grow erect and are unbranched or sparsely branched. The alternate

leaves A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...

consist of a petiole and a simple blade. The basal leaves are often forming a rosette. The leaf blade is triangular-hastate to ovate, sometimes with elongated lobes, with entire or dentate margins and an acute apex. The plants are usually

dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproducti ...

, (rarely

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

). The male flowers are in glomerules forming interrupted terminal spike-like panicles. They consist of 4-5 oblong

perianth The perianth (perigonium, perigon or perigone in monocots) is the non-reproductive part of the flower, and structure that forms an envelope surrounding the sexual organs, consisting of the calyx (sepals) and the corolla ( petals) or tepals when ...

segments and 4-5

stamens The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filame ...

. Female flowers are in glomerules sitting in the leaf axils. Enclosed by 2 accrescent or united bracteoles, without perianth, they consist of an ovary with 4-5 filiform stigmas. In fruit, bracteoles become enlarged and hardened, sometimes with dentate margins, sometimes several flowers becoming connate. The membranous pericarp adheres to the vertically orientated seed. The dark seed coat is spiny or smooth. The embryo is annular, surrounding the copious, farinaceous perisperm. The

chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins ar ...

base number is x = 6, which is unusual for

Distribution

The genus ''Spinacia'' was originally distributed in temperate

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

, and has been introduced to the

mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on ...

area early. ''Spinacia oleracea'' grows cultivated or naturalized in all temperate and

subtropical The subtropical zones or subtropics are geographical and climate zones to the north and south of the tropics. Geographically part of the temperate zones of both hemispheres, they cover the middle latitudes from to approximately 35° north a ...

regions of

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

, Asia, and

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

Systematics

The genus ''Spinacia'' was first described in 1753 by

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, ...

in ''

Species Plantarum ' (Latin for "The Species of Plants") is a book by Carl Linnaeus, originally published in 1753, which lists every species of plant known at the time, classified into genera. It is the first work to consistently apply binomial names and was the ...

'', 2, p. 1027. Type species is '' Spinacia oleracea''. The genus name may derive from the Latin "spina" or from Persian "ispanakh" (=spine), referring to the spiny fruit. ''Spinacia'' is closely related to genus '' Blitum'', both grouping in Tribus Anserineae (Syn. Spinacieae). The genus ''Spinacia'' comprises 3 species: * '' Spinacia oleracea'' L., spinach: only cultivated, probably originating from Southwest Asia. * '' Spinacia tetrandra'' Steven ex M. Bieb.: in

Caucasus The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, Azerbaijan, Georgia, and parts of Southern Russia. The Caucasus Mountains, including the Greater Caucasus range, have historica ...

region (Armenia, Azerbaijan) and

Western Asia Western Asia, West Asia, or Southwest Asia, is the westernmost subregion of the larger geographical region of Asia, as defined by some academics, UN bodies and other institutions. It is almost entirely a part of the Middle East, and includes A ...

(Iran, Iraq, Jordan, Syria, eventually Turkey). * '' Spinacia turkestanica'' Iljin: in Western Asia (Iran) and

Middle Asia Middle or The Middle may refer to: * Centre (geometry), the point equally distant from the outer limits. Places * Middle (sheading), a subdivision of the Isle of Man * Middle Bay (disambiguation) * Middle Brook (disambiguation) * Middle Creek ...

(Afghanistan, Kazakhstan, Turkmenistan, southern Russia, Pakistan, India, Tibet).

References

Leila M. Shultz
''Spinacia'', p. 302 - online
In: Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico. Volume 4: Magnoliophyta: Caryophyllidae, part 1. Oxford University Press, New York u.a. 2003, . Gelin Zhu, Sergei L. Mosyakin & Steven E. Clemants: ''Chenopodiaceae''
''Spinacia'', p. 366 - online
In: Wu Zhengyi, Peter H. Raven, Deyuan Hong (Ed.): ''Flora of China'', Volume 5: ''Ulmaceae through Basellaceae.'', Science Press und Missouri Botanical Garden Press, Beijing und St. Louis, 2003, . 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. 16. ''Spinacia''
''Germplasm Resources Information Network'' - (GRIN) nline Database accessed 2013-07-10. .''Species plantarum'' at BHL
/ref> Pertti Uotila: ''Spinacia''. In: Karl Heinz Rechinger et al. (Ed.): Flora Iranica, Vol. 172 - Chenopodiaceae. Graz, Akad. Druck, 1997, p.59-63.

External links

{{Authority control Chenopodioideae Amaranthaceae genera Dioecious plants