It is anannual plant (rarelybiennial), growing as tall as 30 cm (1 ft). Spinach mayoverwinter intemperate regions. Theleaves are alternate, simple, ovate to triangular, and very variable in size: 2–30 cm (1–12 in) long and 1–15 cm (1⁄2–6 in) broad, with larger leaves at the base of the plant and small leaves higher on the flowering stem. Theflowers are inconspicuous, yellow-green,3–4 mm (1⁄8–5⁄32 in) in diameter, and mature into a small, hard, dry, lumpyfruit cluster5–10 mm (1⁄4–3⁄8 in) across containing severalseeds.
In 2022, world production of spinach was 33 milliontonnes, with China alone accounting for 93% of the total.[1]
As opposed to mostflowering plants used as vegetables, spinach is adioecious plant, meaning different plants can have either female or male flowers.[a][7]The flowers are small, green andwind pollinated.
Spinach is thought to have originated about 2,000 years ago inancient Persia from which it was introduced toIndia and later toancient China viaNepal in 647 CE as the "Persian vegetable".[8] In 827 CE, theArabs introduced spinach toSicily.[9] The first written evidence of spinach in theMediterranean was recorded in three 10th-century works: a medical work by al-Rāzī (known asRhazes in the West) and in two agricultural treatises, one by Ibn Waḥshīyah and the other by Qusṭus al-Rūmī. Spinach became a popular vegetable in the Arab Mediterranean and arrived in the Iberian Peninsula by the latter part of the 12th century, where Ibn al-ʻAwwām called itraʼīs al-buqūl, 'thechieftain ofleafy greens'.[10] Spinach was also the subject of a special treatise in the 11th century by Ibn Ḥajjāj.[11][better source needed]
Spinach first appeared in England and France in the14th century, probably via Iberia, and gained common use because it appeared in early spring when fresh local vegetables were not available.[8] Spinach is mentioned in the first known Englishcookbook, theForme of Cury (1390), where it is referred to as 'spinnedge' and 'spynoches'.[8][12] DuringWorld War I, wine fortified with spinach juice was given to injuredFrench soldiers with the intent to curtail theirbleeding.[8][13]
Although spinach contains moderate amounts of iron and calcium, it also containsoxalates, which may inhibit absorption of calcium and iron in the stomach and small intestine. Cooked spinach has lower levels of oxalates, and its nutrients may be absorbed more completely.[16][17]
Cooking spinach significantly decreases its vitamin C concentration, as vitamin C is degraded by heating. Folate levels may also be decreased, as folate tends to leach into cooking liquid.[18]
Spinach is rich innitrates andnitrites, which may exceed safe levels if spinach is over-consumed.[19]
Fresh spinach is sold loose, bunched, or packaged fresh in bags. Fresh spinach loses much of its nutritional value with storage of more than a few days.[21] Fresh spinach is packaged in air, or in nitrogen gas to extend shelf life. While refrigeration slows this effect to about eight days, fresh spinach loses most of its folate and carotenoid content over this period of time. For longer storage, it iscanned, or blanched or cooked and frozen.[21]
Some packaged spinach is exposed to radiation to kill any harmful bacteria. TheFood and Drug Administration approves of irradiation of spinach leaves up to anabsorbed dose of 4.0kilograys, having no or only a minor effect on nutrient content.[22]
Spinach may be high incadmium contamination depending on the soil and location where the spinach is grown.[23]
Due to spinach's high content of vitamin K, individuals taking theanticoagulantwarfarin, which acts by inhibiting vitamin K, are instructed to minimize consumption of spinach (and other dark green leafy vegetables).[24]
The comics and cartoon characterPopeye the Sailor Man is portrayed as gaining strength by consuming canned spinach.[27] The accompanying song lyric is: "I'm strong to the finich [sic], 'cuz I eats me spinach."[28] This is usually attributed to theiron content of spinach, but in a 1932 strip, Popeye states that "spinach is full ofvitamin A" and that is what makes people strong and healthy.[29] As it happens, spinach is not a better source of dietary iron than many other vegetables. The false idea that spinach is an especially good source of dietary iron is an academicurban legend.[30]
^Birlouez, Éric (2020). "Une fabuleuse diversité, «L'épinard, légume de carème»" [A fabulous diversity, «Spinach, the lent vegetable»].Petite et grande histoire des légumes [A small and great history of vegetables]. Carnets de sciences (in French) (1 ed.). Versailles/impr. en Suisse: Quæ. p. 52-54.ISBN978-2-7592-3196-6.Quæ
^Clifford A. Wright.Mediterranean Vegetables: A Cook's ABC of Vegetables and their Preparation in Spain, France, Italy, Greece, Turkey, the Middle East, and North Africa, with More than 200 Authentic Recipes for the Home Cook. (Boston: Harvard Common Press, 2001). pp. 300-301.
^"The Press: I Say It's Spinach".Time. October 22, 1951. RetrievedFebruary 1, 2014.Many a New Yorkerism (e.g., Cartoonist Carl Rose's 'I say it's spinach, and I say the hell with it') has become a part of the language.
^Joe Schwarcz,Monkeys, Myths, and Molecules: Separating Fact from Fiction in the Science of Everyday Life, 2015,ISBN1770411917, p. 245; spinach actually containsbeta-carotene, which the body converts to vitamin A
