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| Latin: |
Asparagus officinalis |
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| Origin: |
Asparagus belongs to the family Asparagaceae with about 300 species; it is native from Siberia to southern Africa. Related to the lily family, asparagus has a slender green stalk with a distinctive but elusive flavor and a mildly astringent undertone. Best known is the garden asparagus, Asparagus officinalis L., cultivated as a green vegetable for its succulent spring stalks. Several African species are grown as ornamental plants.
Asparagus may be erect or climbing, and most of the species are more or less woody. The rhizome-like, or sometimes tuberous, roots give rise to conspicuous, leaflike branchlets; true leaves are reduced to small scales. Small, greenish-yellow flowers are in August, followed by red berries in the fall. The flowers are dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required) and are pollinated by bees. The plant can grow in semi-shade (light woodland) or no shade. It requires moist soil, and can tolerate maritime exposure.
Garden, or green, asparagus, the most economically important and the most common species of the genus, is cultivated in most temperate and subtropical parts of the world. As a vegetable it has been prized by connoisseurs since Roman times. Long revered in European cuisine, it's finding its way more frequently into American cooking.
White asparagus, which is grown underground to prevent chlorophyll from developing and turning it green, has thicker, smoother spears. It's harder to find, but worth the effort.
A less frequently seen variety is purple asparagus, called viola, which actually turns green during cooking.
The world's leading producers of asparagus are Peru, the United States, and Spain. The vegetable is also grown extensively in China, Morocco, France, Italy, and Mexico.
Commercial plantations are not undertaken in regions where the plant continues to grow throughout the year, for the shoots become more spindly and less vigorous each year; a rest period is required. Where climate is favorable and with proper care, an asparagus plantation may be productive for 10 to 15 years or longer.
The best soil types for asparagus are deep, loose, light clays, with much organic matter, and light, sandy loams. Asparagus will thrive in soils too salty for other crops, but acid soils are to be avoided.
The asparagus cutting season varies from 2 to 12 weeks, depending on age of the plantation and on climate. Do not overharvest the plant because this would weaken it in the following year.
The roots are harvested in late spring, after the shoots have been cut as a food crop, and are dried for later use as herb. The peak season for fresh asparagus lasts from February through June; hothouse asparagus is available year-round in some regions. Asparagus is also available canned and frozen. |
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| Properties: |
| Slightly pungent and bitter in flavor, warm in nature, it is related to the kidney and lung channels. |
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| Functions: |
Lubricates the lungs, relieves cough, expels sputum, destroys worms.
Asparagus has been cultivated for over 2,000 years as a vegetable and medicinal herb. Both the roots and the shoots can be used medicinally, they have a restorative and cleansing effect on the bowels, kidneys and liver. |
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| Applications: |
| Asparagus is used to treat dry cough, lung heat and lymphatic tuberculosis. |
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| Dosage and Administration: |
Youn asparagus shoot is most commonly served cooked, either hot or in salad. It can also be eaten raw. The classic accompaniment is hollandaise sauce.
Asparagus is normally boiled or steamed and used as a vegetable. Male plants produce the best shoots.
Because asparagus is grown in sandy soil, asparagus should be washed thoroughly to remove any dirt or grit. Snap any tough ends off and immerse the stalks in boiling salted water. Reduce heat, simmer, and remove after about five minutes, while still bright green. Toss with olive oil and serve hot. Asparagus is also good in stir-fry dishes.
Asparagus can be found in the produce section of most health food stores, specialty markets, and supermarkets. When buying asparagus, choose firm, bright green (or pale ivory) stalks with tight tips. Wider spears are from older plants, and slender spears from younger ones; both are tender and flavorful. Store asparagus tightly wrapped in a plastic bag for up to three days in the refrigerator. It may also be stored standing upright, with the stems immersed in about 2 cm of water and the tops covered with plastic. |
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| Cautions on Use: |
Large quantities of the shoots can irritate the kidneys. The berries are mildly poisonous.
In addition, there are several poisonous species but they are prized for their delicate and graceful foliage:
Asparagus plumosus, the asparagus fern, or florists' fern (not a true fern), which has feathery sprays of branchlets often used in corsages and in other plant arrangements; and
Asparagus sprengeri and Asparagus asparagoides, likewise grown for their attractive, lacy foliage. |
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| Reference Materials: |
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| Toxic or Side Effects: |
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| Modern Researches: |
Asparagus has high nutritional value. Each 1,000 g of fresh asparagus contains 25 g protein, 2 g fat, 50 g carbohydrates, 7 g crude fiber, 220 mg calcium, 620 mg phosphorus, 20 mg sodium, 200 mg magnesium, 2.78 g potassium, 10 mg iron, 0.4 mg copper, 15 mg niacin, 6.2 mg pantothenic acid, 1.09 mg folic acid, 17 mg biotin, can emit heat 109.2 kj; as well as vitamin A, vitamin C, vitamin B1, vitamin B2, and vitamin B6.
The plant is antispasmodic, laxative, cardiac, soothing, diaphoretic (having the power to increase perspiration), diuretic (tending to increase the flow of urine), sedative and tonic. The freshly expressed juice is used.
The root is diaphoretic, strongly diuretic and laxative. An infusion is used in the treatment of jaundice and congestive torpor (insensitivity, stagnation of function) of the liver. The strongly diuretic action of the roots make it useful in the treatment of a variety of urinary problems including cystitis (inflammation of the urinary bladder). The roots are said to be able to lower blood pressure.
Asparagus root is also used in the treatment of cancer. The strong association between increased intake of beta-carotene from food and a reduced risk of lung cancer does not necessarily mean that supplementation with natural beta-carotene supplements would reduce the risk of lung cancer. Dietary beta-carotene may be a marker for diets high in certain fruits and vegetables that contain other anticancer substances that may be responsible for the protective effects. Until more is known, some doctors advise smokers to avoid all forms of beta-carotene supplementation--even natural beta-carotene.
The seeds possess antibiotic activity. Another report says that the plant contains asparagusic acid which is nematocidal (destructive to nematode worms) and is used in the treatment of schistocystis (fissure or crack of the bladder).
Roasted seeds are a coffee substitute. |
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