Asparagus

Asparagus officinalis is a plant species in the family Asparagaceae from which the popular vegetable known as asparagus is obtained. The species probably originated in the eastern Mediterranean region but is now a widely-cultivated vegetable crop.

Biology
Asparagus officinalis is native to maritime areas around the Mediterranean. Traditionally placed among the Liliaceae, some authorities split out the Asparagaceae as a separate family. Only the young shoots of asparagus are eaten, before they expand into feathery growth about 100-150cm high. The 'leaves' are in fact needle-like cladodes (modified stems) in the axils of scale leaves. Male and female flowers are normally borne on separate plants, but sometimes hermaphrodite flowers are found. Flowers are found in the junctions of the branchlets, singly or in groups of 2-3. The fruit is a small red berry.

Asparagus is low in calories, contains no fat or cholesterol, and is very low in sodium. It is good source of folic acid, potassium, fiber, and rutin. The amino acid asparagine gets its name from asparagus, the asparagus plant being rich in this compound.

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.It lost its popularity in the Middle Ages but returned to favour in the 17th century.

Culinary
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.

Medicinal
Asparagus rhizomes and root is used ethnomedically to treat urinary tract infections, as well as kidney and bladder stones.

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 metabolized and excreted in the urine, giving it a distinctive odor. The odor 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 the odor. The speed of onset of urine smell is rapid, and has been estimated to occur within 15-30 minutes from ingestion.

Legend has it that a gentlemen's club in London, reputedly the Garrick, had a notice saying "During the asparagus season members are requested not to relieve themselves into the umbrella stand."

Cultivation
Since asparagus 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.

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 tons (61% of consumer demands) are produced annually.

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.

Commercial production
Peru is currently the world’s leading asparagus exporter, followed by China and Mexico. The top asparagus importers (2004) were the United States (92,405 tons), followed by the European Union (external trade) (18,565 tons), and Japan (17,148 tons). The United States' production for 2005 was on 54,000 acres (220 km²) and yielded 90,200 tons, making it the world's largest producer and consumer. Production was concentrated in California, Michigan, and Washington. 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." 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, and in German Spargel.