Asparagus officinalis is a flowering plant species in the genus Asparagus from which the popular vegetable known as
asparagus is obtained. It is native to most of Europe, northern Africa and western Asia.[1][2][3] It is now also widely cultivated as a vegetable crop.[4]
Biology
It is a herbaceous perennial plant growing
to 100-150 cm tall, with stout stems with much-branched feathery foliage. The 'leaves' are in fact needle-like cladodes (modified
stems) in the axils of scale leaves; they are 6–32 mm long and 1 mm broad, and clustered 4–15 together. The flowers are bell-shaped, greenish-white to yellowish, 4.5–6.5 mm long, with six tepals partially fused together at the base; they are produced singly or in clusters of 2-3 in the junctions of
the branchlets. It is usually dioecious, with male and female flowers on separate
plants, but sometimes hermaphrodite flowers are found. The fruit is a small red berry 6–10 mm
diameter.[5]
Plants native to the western coasts of Europe (from northern Spain north to Ireland, Great Britain, and northwest Germany) are treated as Asparagus officinalis subsp. prostratus (Dumort.) Corb., distinguished by
its low-growing, often prostrate stems growing to only 30–70 cm high, and shorter cladodes 2–18 mm long.[1][5] It is treated as a distinct species Asparagus prostratus Dumort. by some authors.[6][7]
History
Asparagus has been used from very early times as a vegetable and medicine, owing to its delicate flavour and diuretic properties. There is a recipe for cooking asparagus in the oldest
surviving book of recipes, Apicius's 3rd century AD De re
coquinaria, Book III. It was cultivated by the ancient Egyptians, Greeks and Romans, who ate it fresh when in season
and dried the vegetable for use in winter.[verification needed] It lost its popularity in the
Middle Ages but returned to favour in the 17th century.[8]
Uses
Culinary
Two types of asparagus on a shop display, with white asparagus at the back and green asparagus in the middle. The plant at the
front is
Ornithogalum pyrenaicum, sometimes called "Bath
Asparagus".
Only the young shoots of asparagus are eaten. Asparagus is low in calories, contains no fat or cholesterol, and is very low in
sodium. It is good source of folic acid, potassium,
dietary fibre, and rutin. The amino acid asparagine gets its name from asparagus, the asparagus plant
being rich in this compound.
The shoots can be prepared and served in a number of ways, but are usually boiled or steamed and served with hollandaise sauce, melted butter or olive oil and Parmesan cheese. Tall asparagus cooking pots allow the shoots to be steamed gently. Cantonese restaurants in the United States often serve asparagus
stir-fried with chicken, shrimp, or beef, also wrapped in bacon. Asparagus may also be quickly grilled over charcoal or
hardwood embers. The best asparagus tends to be early growth (first of the season) and is normally simply steamed and served with
melted butter.
The bottom portion of asparagus often contains sand, and as such proper preparation is generally advised in cooking asparagus.
A case of botulism borne on asparagus was recorded in Australia in 1991.[9]
Medicinal
Asparagus rhizomes and root is used ethnomedically to
treat urinary tract infections, as well as kidney and bladder stones[citation needed]. It is also believed to have
aphrodisiac properties[citation needed].
Asparagus pee
Proust claimed that asparagus "...as in a Shakespeare fairy-story transforms my chamber-pot into a flask of perfume".
Some of the constituents of asparagus are metabolised and excreted in the urine, giving it a distinctive smell. This is due to various sulfur-containing degradation products (e.g.
thiols and thioesters) and ammonia. Recent studies suggest that
every individual produces the odorous compounds upon eating, but that only about 40% of individuals have the genes required to
smell them.[10][11] The speed of onset of urine smell is rapid, and has been estimated to occur
within 15-30 minutes from ingestion.[12]
Cultivation
- See also: List of asparagus
diseases
Since asparagus often originates in maritime habitats, it thrives in soils that are too saline for normal weeds to grow in.
Thus a little salt was traditionally used to suppress weeds in beds intended for asparagus; this has the disadvantage that the
soil could not be used for anything else. 'Crowns' are planted in Winter, and the first shoots appear in Spring; the first
pickings or 'thinnings' are known as sprue asparagus. Sprue have thin stems.[13]
White asparagus, known as spargel is cultivated by denying the plants light and increasing
the amount of ultraviolet light the plants are exposed to while they are being grown. Less bitter than the green variety, it is
very popular in the Netherlands and Germany where 57,000 tonnes (61% of consumer demands) are
produced annually.[14]
Purple asparagus differs from its green and white counterparts, having high sugar and low fibre
levels. Purple asparagus was originally developed in Italy and commercialised under the variety
name Violetto d'Albenga. Since then, breeding work has continued in countries such as the United States and New
Zealand.[verification needed]
Commercial production
Peru is currently the world's leading asparagus exporter, followed by China and Mexico.[15] The top asparagus importers (2004) were the United States (92,405 tonnes), followed by the
European Union (external trade) (18,565 tonnes), and Japan
(17,148 tonnes).[16] The United States' production for 2005
was on 21,850 hectares (54,000 acres) and yielded 90,200 tonnes, making it the world's largest producer and consumer. Production
was concentrated in California, Michigan,
and Washington.[17] The crop is significant enough in California's Sacramento-San Joaquin River Delta region that the city of Stockton holds a festival every year to celebrate it.
The Vale of Evesham is the traditional centre of the UK industry; British asparagus
has a more delicate flavour than that grown in hotter climates.
Vernacular names and etymology
Asparagus officinalis is widely known simply as "asparagus", and may be confused with unrelated plant species also
known as "asparagus", such as Ornithogalum pyrenaicum known as "Prussian
asparagus" for its edible shoots.
The English word "asparagus" derives from classical Latin, but the plant was once known in
English as sperage, from the Medieval Latin sparagus. This term itself
derives from the Greek aspharagos or asparagos, and the Greek term
originates from the Persian asparag, meaning "sprout" or "shoot".
Asparagus was also corrupted in some places to "sparrow grass"; indeed, John
Walker stated in 1791 that "Sparrow-grass is so general that asparagus has an air of stiffness and
pedantry". [citation needed] Another known colloquial variation of the term, most common in parts of
Texas, is "aspar grass" or "asper grass". Asparagus is commonly known in fruit retail circles as "Sparrows Guts", etymologically
distinct from the old term "sparrow grass", thus showing convergent language evolution.
It is known in French and Dutch as
asperge, in Portuguese as espargo hortense, in Spanish as esparrago, and in German Spargel.
References
- ^ a b Flora Europaea: Asparagus officinalis
- ^ Euro+Med Plantbase Project: Asparagus officinalis
- ^ Germplasm Resources Information Network: Asparagus
officinalis
- ^ Grubben, G.J.H. & Denton, O.A. (2004) Plant Resources of
Tropical Africa 2. Vegetables. PROTA Foundation, Wageningen; Backhuys, Leiden; CTA, Wageningen.
- ^ a b Blamey, M. & Grey-Wilson, C. (1989). Flora of Britain and Northern
Europe. ISBN 0-340-40170-2
- ^ Flora of NW Europe: Asparagus prostratus
- ^ Germplasm Resources Information Network: Asparagus
prostratus
- ^ Vaughan, J.G.;
Geissler, C.A. (1997). The New Oxford Book of Food Plants. Oxford University Press.
- ^ Hocking, A.D.. Foodborne Microorganisms of Public Health Significance. Foodborne Microorganisms of Public Health Significance.
- ^ Stevens, R. J. G. (August , 2000).
"Why does urine
smell odd after eating asparagus?". studentBMJ. Retrieved on 2006-08-31.
- ^ The scientific chef: asparagus pee. The Guardian (September 23, 2005). Retrieved on
2007-04-21.
- ^ Somer, E. (August 14, 2000). Eau D'Asparagus. WebMD. Retrieved
on 2006-08-31.
- ^ BBC - Food - Glossary - 'S'. BBC Online. Retrieved on 2007-06-08.
- ^ Molly Spence. Asparagus:
The King of Vegetables. German Agricultural Marketing Board. Retrieved on 2007-02-26.
- ^ United States Department of Agriculture. World
Asparagus Situation & Outlook. World Horticultural Trade & U.S. Export Opportunities. Retrieved on 2007-02-27.
- ^ According to Global Trade Atlas and U.S. Census Bureau statistics
- ^ USDA (January 2006).
Vegetables 2005 Summary. National Agricultural Statistics Service.
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