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{{Taxobox
| color = lightgreen
| name = Dandelion
| image = Macro dandelion Fcb981.JPG
| image_width = 250px
| regnum = [[Plant]]ae
| divisio = [[Flowering plant|Magnoliophyta]]
| classis = [[Dicotyledon|Magnoliopsida]]
| ordo = [[Asterales]]
| familia = [[Asteraceae]]
| genus = '''''Taraxacum'''''
| genus_authority = [[Alexandre Henri Gabriel de Cassini|Cass.]]
| subdivision_ranks = Species
| subdivision = See text
}}
A '''dandelion''' is a flower. A dandelion [[Head (botany)|flower head]] consists of many tiny flowers. The dandelion is native to Europe and Asia, and has spread to many other places. The dandelion is also known by its genera name ''Taraxacum''. In northern areas and places where the dandelion is not native, it reproduces asexually.
==Description==
'''Dandelion''' ('''''Taraxacum''''') is a large [[genus]] of [[flowering plant]]s in the family [[Asteraceae]]. They are [[taproot|tap-rooted]] [[Biennial plant|biennial]] or [[perennial plant|perennial]] [[herbaceous]] plants, native to [[temperate]] areas of the [[Northern Hemisphere]] of the [[Old World]]. They are known as pests or weeds to the common person.
[[Image:Tom's pictures2 005.jpg|left|thumb|A flowering dandelion.]]
The genus is [[taxonomy|taxonomically]] very complex, with numerous macrospecies, and [[polyploid]]y is also common; over 250 species have been recorded in the [[British Isles]] alone (Richards 1972). Some botanists take a much narrower viewpoint, and only accept a total of about 60 species.
The leaves are 5-25 cm long, simple and basal, entire or lobed, forming a rosette above the central taproot. As the leaves grow outward they push down the surrounding vegetation, such as grass in a lawn, killing the vegetation by cutting off the sunlight. A bright yellow [[inflorescence|flower head]] (which is open in the daytime but closes at night) is borne singly on a hollow stem (scape) which rises 4-30 cm above the leaves and exudes a milky [[Sap (plant)|sap]] ([[latex]]) when broken. A rosette may produce several flowering stems at a time. The flower head is 2-5 cm in diameter and consists entirely of ray [[floret]]s.
Dandelions are used as food plants by the [[larva]]e of some species of [[Lepidoptera]]. See [[List of Lepidoptera which feed on Dandelions]].
Away from their native regions, they have become established in the [[Americas]], [[Australia]] and [[New Zealand]] as [[weed]]s. They are now common plants throughout all temperate regions.
===Dandelion clock===
[[Image:Taraxacum seed 1.jpg|left|thumb|A dandelion clock.]]
The flower matures into a globe of fine filaments that are usually distributed by wind, carrying away the seed-containing [[achene]]s. This globe (receptacle) is called the "clock", and blowing it apart is a popular activity for children worldwide.
===Seeds===
[[Image:Photos-photos 1088103921 Floating.jpg|thumb|right|[[Macro photography|Macro]] photo of dandelion seed dispersal.]]
The flower head is surrounded by [[bract]]s (sometimes mistakenly called sepals) in two series. The inner [[bract]]s are erect until the seeds mature, then flex down to allow the seeds to disperse; the outer bracts are always reflexed downward. Some species drop the "parachute" (called a ''pappus'', modified sepals) from the achenes. Between the pappus and the achene, there is a stalk called a beak, which elongates as the fruit matures. The beak breaks off from the achene quite easily.
==Name==
[[Image:Loewenzahn bluete unten.jpg|thumb|]]
The name ''dandelion'' is derived from the Old French, ''dent-de-lion'', which is literally "lion's tooth", referring to the sharply-lobed leaves of the plant. The English spelling reflects the French pronunciation at the time this French word was absorbed into English.<ref name="CBC">{{cite news |url=http://www.cbc.ca/news/background/living-green/dandelions.html|publisher=CBC.ca In Depth|title=Living Green, Dandelions: Time to throw in the trowel - Pesticide bylaws make it easier|date=Jun 13, 2007 |accessdate=2007-06-14
}}</ref> The first written usage of the word occurs in a [[he
rbal]] dated 1373, but there is a 1363 document in which the word "dandelion" was used as a proper name (Willelmus Dawndelyon).
In Norwegian, the ''dandelion'' is called ''Løvetann'', which is also translated as "lion's tooth", also ''Löwenzahn'' ("lions' tooth") in German. In modern French the plant is called ''pissenlit'', which means "urinate in bed", apparently referring to its [[diuretic]] properties. Likewise, "pissabeds" is an English folkname for this plant, and "piscialletto" is one of its folknames in [[Italian language|Italian]] (with "dente di leone", meaning "lion's tooth"). Similarly in Spanish, it is known as the "meacamas", but also commonly "diente de león". In Portuguese, its common name is "dente-de-leão" meaning also "lion's tooth". In Turkish the dandelion is called "karahindiba" meaning "black endive". Hungarian names are ''kutyatej'' ("dog milk", referring to the white sap found in the stem) and ''gyermekláncfű'' ("child's chain grass", referring to the habit of children to pick dandelions, remove the flowers, and make links out of the stems by "plugging" the narrow top end of the stem into the wider bottom end).
==Selected species==
* ''[[Taraxacum officinale]]'' (syn. ''T. officinale subsp. vulgare''), Common Dandelion. Found in many forms, but differs at least from the following species:
* ''[[Taraxacum albidum]]'', a white-flowering [[Japan]]ese dandelion.
* ''[[Taraxacum japonicum]]'', Japanese dandelion. No ring of smallish, downward-turned leaves under the flowerhead.
* ''[[Taraxacum laevigatum]]'' (syn. ''T. erythrospermum''), Red-seeded Dandelion; achenes reddish brown and leaves deeply cut throughout length. Inner bracts' tips are hooded.
==Seed development and genetics==
As aforementioned, the taxonomical situation of the genus is quite complex, mainly because many dandelions are genetically [[polyploidy|triploid]]. An odd number of [[chromosomes]] usually is associated with [[infertility|sterility]], but dandelions with this [[karyotype]] can reproduce without [[fertilization]], a process called [[apomixis]]<ref>http://www.talkorigins.org/faqs/comdesc/section2.html#vestiges</ref>. In these individuals [[flower]]s are useless [[vestigial]] structures, although they may still produce a small percentage of fertile [[pollen]], keeping some genetic contact with sexual individuals. Diploid dandelions develop seeds after cross-[[pollination]] and are self-incompatible. In most zones of southern [[Europe]] and [[Asia]], dandelion populations are sexual or mixed sexual-apomictic, while in northern countries only triploid and tetraploid apomicts are present, as is in the zones where it is not native. This seems to be linked to higher temperatures, survival of pre-glacial populations and human impact, but the subject is still being studied.
There are usually 54 to 172 seeds produced per head, but a single plant can produce more than 2000 seeds a year. It has been estimated that more than 97 000 000 seeds/[[hectare]] could be produced every year by a dense stand of dandelions.
==Dandelion Snow==
After pollination, the dandelion flower dries out for about 10 days and then the seed-bearing parachutes expand and lift out of the dried flower head. The dried part of the flower drops off and the parachute ball opens into a full sphere. The parachute drops off when the seed strikes an obstacle. Often dandelions can be observed growing in a crevice near a wall, because the blowing fruits hit the wall and the feathery pappi drop off, sending the dandelion seeds to the base of the obstacle where they germinate. After the seed is released, the parachutes lose their feathered structure and take on a fuzzy, cotton-like appearance, often called "dandelion snow."
==Uses==
[[Image:Dandelion Blackwell 0136.jpg|thumb|right|The dandelion's [[taproot]], shown in this drawing, makes this plant very difficult to uproot; the top of the plant breaks away, but the root stays in the ground and can sprout again.]]
While the dandelion is considered a [[weed]] by many gardeners and lawn owners, the plant does have seve
ral [[culinary]] and [[herb|medicinal]] uses. Dandelions are grown commercially at a small scale as a [[leaf vegetable]]. The plant can be eaten cooked or raw in various forms, such as in [[soup]] or [[salad]]. They are probably closest in character to [[Mustard plant|mustard]] greens. Usually the young leaves and unopened buds are eaten raw in salads, while older leaves are cooked. Raw leaves have a slightly bitter taste. Dandelion salad is often accompanied with hard boiled [[egg (food)|egg]]s. The leaves are high in [[vitamin A]], [[vitamin C]] and [[iron]], carrying more iron and [[calcium]] than [[spinach]].<ref>[http://www.wildmanstevebrill.com/Plants.Folder/Dandelion.html An article about dandelion nutrition.]</ref>
Dandelion flowers can be used to make dandelion [[wine]]. The recipe usually contains [[citrus fruit]]. Another recipe using the plant is dandelion flower jam. Ground roasted dandelion root can be used as a [[coffee]] substitute. Drunk before meals, it is believed to stimulate digestive functions. Sold in most health food stores, often in a mixture, it is considered an excellent cleansing tonic for the liver.
{{main|Medicinal properties of dandelion}}
Dandelion root is a registered drug in [[Canada]], sold as a [[diuretic]]. Dandelions are so potent in this effect, that children have been known to wet the bed the night after skin contact from playing with them.<ref name="CBC"/> A leaf decoction can be drunk to "purify the blood", for the treatment of anemia, jaundice, and also for nervousness. The milky latex has been used as a mosquito repellent; the milk is also applied to warts, helping get rid of them without damaging the surrounding skin. A dye can also be obtained from the roots of the plant. A new mixture of roasted roots is sold as a product called DandyBlend which tastes like coffee after the [[inulin]] in the dandelion is roasted.
"[[Dandelion and burdock|Dandelion and Burdock]]" is a soft drink that has long been popular in the [[United Kingdom]] with authentic recipes sold by health food shops. It is unclear whether cheaper supermarket versions actually contain either plant.
This plant also is useful in farming, because its deep, strong roots break up [[hardpan]].
===Antioxidant properties===
Dandelion contains luteolin, an [[antioxidant]], and has demonstrated antioxidant properties without [[cytotoxicity]].<ref>Chun Hu and David D. Kitts. Food, Nutrition and Health, Faculty of Agricultural Sciences, University of British Columbia, Vancouver, BC, Canada. October 2004. Luteolin and luteolin-7-O-glucoside from dandelion flower suppress iNOS and COX-2 in RAW264.7 cells. Springer Netherlands. '''245''':1-2(107-113). </ref>[http://www.springerlink.com/content/qg16p71737602150/]
===Caffeic acid and carcinogenicity===
[[Caffeic acid]] is a secondary plant metabolite produced in dandelion, [[yarrow]], [[horsetail]] and [[whitethorn]]. Despite its name, it is totally unrelated to [[caffeine]]. Recent studies have revealed this acid may be [[carcinogenic]]. Caffeic acid was tested for carcinogenicity by oral administration in mice, it produced renal cell [[adenoma]]s in females, and a high incidence of renal tubular cell [[hyperplasia]] in animals of each sex.<ref>''Caffeic acid phenethyl ester is a potent and specific inhibitor of activation of nuclear transcription factor NF-kappa B.'', Natarajan K, Singh S, Burke TR Jr, Grunberger D, Aggarwal BB., Proc. Natl. Acad. Sci. U S A., 1996 Aug 20;93(17):9090-5.</ref> However, more recent research shows that [[bacteria]] present in the rats' guts may alter the formation of [[metabolite]]s of caffeic acid. [http://www.pnas.org/cgi/content/abstract/69/6/1413] and [http://jn.nutrition.org/cgi/content/full/133/6/1853] Also, there have been no known ill-effects of caffeic acid in humans.
==False dandelions==
Dandelions are so similar to [[catsear]]s (''Hypochoeris'') that catsears are also known as "false dandelions." Both plants carry similar flowers which form into windborne seeds. However, catsear flowering stems are forked and solid, whereas da
ndelions possess unforked stems that are hollow. Both plants have a rosette of leaves and a central taproot. However, the leaves of dandelions are jagged in appearance, whereas those of catsear are more lobe-shaped and hairy.
Other plants with similar flowers include [[hawkweed]]s (''Hieracium'') and [[crepis|hawksbeard]]s (''Crepis''). These are both readily distinguished by their branched flowering stems.
<div style="clear: both"></div>
==See also==
* [[List of beneficial weeds]]
* [[List of companion plants]]
==References and external links==
{{commonscat|Taraxacum}}
* Richards, A. J. 1972. The ''Taraxacum'' flora of the British Isles. ''Watsonia'' 9 (supplement): 1-141.
* Gail, Peter. ''The Dandelion Celebration: A Guide to Unexpected Cuisine''. Cleveland, Ohio: Goosefoot Acres Press, 1994. ISBN 1-879863-51-0.
*[http://en.wikibooks.org/wiki/Transwiki:How_to_cook_dandelions How to cook dandelions] ~ at ''Wikibooks''
* [http://fxcuisine.com/default.asp?Display=78 Dandelion Syrup - step-by-step illustrated recipe in English]
*[http://fohn.net/dandelion-pictures/ Dandelion Poetry, Folklore, Literature, and Pictures]
*[http://www.pfaf.org/database/plants.php?Taraxacum+officinale&CAN=WIKIPEDIA Dandelion at Plants For A Future]
*[http://ipcm.wisc.edu/uw_weeds/extension/articles/dandelion.htm a university of Wisconsin article on dandelions]
*{{cite web|title=SpringerLink|work=Chun Hu and David D. Kitts. Food, Nutrition and Health, Faculty of Agricultural Sciences, University of British Columbia, Vancouver, BC, Canada. October 2004. Luteolin and luteolin-7-O-glucoside from dandelion flower suppress iNOS and COX-2 in RAW264.7 cells. Springer Netherlands. '''245''':1-2(107-113)
|url=http://www.springerlink.com/content/qg16p71737602150/}}
<references/>
[[Category:Asteraceae]]
[[Category:Herbs]]
[[Category:Invasive species]]
[[Category:Leaf vegetables]]
[[Category:Lawn weeds]]
[[Category:Medicinal plants]]
[[Category:Flora of Greenland]]
{{Taxobox
| color = lightgreen
| name = Dandelion
| image = Macro dandelion Fcb981.JPG
| image_width = 250px
| regnum = [[Plant]]ae
| divisio = [[Flowering plant|Magnoliophyta]]
| classis = [[Dicotyledon|Magnoliopsida]]
| ordo = [[Asterales]]
| familia = [[Asteraceae]]
| genus = '''''Taraxacum'''''
| genus_authority = [[Alexandre Henri Gabriel de Cassini|Cass.]]
| subdivision_ranks = Species
| subdivision = See text
}}
A '''dandelion''' is a flower. A dandelion [[Head (botany)|flower head]] consists of many tiny flowers. The dandelion is native to Europe and Asia, and has spread to many other places. The dandelion is also known by its genera name ''Taraxacum''. In northern areas and places where the dandelion is not native, it reproduces asexually.
==Description==
'''Dandelion''' ('''''Taraxacum''''') is a large [[genus]] of [[flowering plant]]s in the family [[Asteraceae]]. They are [[taproot|tap-rooted]] [[Biennial plant|biennial]] or [[perennial plant|perennial]] [[herbaceous]] plants, native to [[temperate]] areas of the [[Northern Hemisphere]] of the [[Old World]]. They are known as pests or weeds to the common person.
[[Image:Tom's pictures2 005.jpg|left|thumb|A flowering dandelion.]]
The genus is [[taxonomy|taxonomically]] very complex, with numerous macrospecies, and [[polyploid]]y is also common; over 250 species have been recorded in the [[British Isles]] alone (Richards 1972). Some botanists take a much narrower viewpoint, and only accept a total of about 60 species.
The leaves are 5-25 cm long, simple and basal, entire or lobed, forming a rosette above the central taproot. As the leaves grow outward they push down the surrounding vegetation, such as grass in a lawn, killing the vegetation by cutting off the sunlight. A bright yellow [[inflorescence|flower head]] (which is open in the daytime but closes at night) is borne singly on a hollow stem (scape) which rises 4-30 cm above the leaves and exudes a milky [[Sap (plant)|sap]] ([[latex]]) when broken. A rosette may produce several flowering stems at a time. The flower head is 2-5 cm in diameter and consists entirely of ray [[floret]]s.
Dandelions are used as food plants by the [[larva]]e of some species of [[Lepidoptera]]. See [[List of Lepidoptera which feed on Dandelions]].
Away from their native regions, they have become established in the [[Americas]], [[Australia]] and [[New Zealand]] as [[weed]]s. They are now common plants throughout all temperate regions.
===Dandelion clock===
[[Image:Taraxacum seed 1.jpg|left|thumb|A dandelion clock.]]
The flower matures into a globe of fine filaments that are usually distributed by wind, carrying away the seed-containing [[achene]]s. This globe (receptacle) is called the "clock", and blowing it apart is a popular activity for children worldwide.
===Seeds===
[[Image:Photos-photos 1088103921 Floating.jpg|thumb|right|[[Macro photography|Macro]] photo of dandelion seed dispersal.]]
The flower head is surrounded by [[bract]]s (sometimes mistakenly called sepals) in two series. The inner [[bract]]s are erect until the seeds mature, then flex down to allow the seeds to disperse; the outer bracts are always reflexed downward. Some species drop the "parachute" (called a ''pappus'', modified sepals) from the achenes. Between the pappus and the achene, there is a stalk called a beak, which elongates as the fruit matures. The beak breaks off from the achene quite easily.
==Name==
[[Image:Loewenzahn bluete unten.jpg|thumb|]]
The name ''dandelion'' is derived from the Old French, ''dent-de-lion'', which is literally "lion's tooth", referring to the sharply-lobed leaves of the plant. The English spelling reflects the French pronunciation at the time this French word was absorbed into English.<ref name="CBC">{{cite news |url=http://www.cbc.ca/news/background/living-green/dandelions.html|publisher=CBC.ca In Depth|title=Living Green, Dandelions: Time to throw in the trowel - Pesticide bylaws make it easier|date=Jun 13, 2007 |accessdate=2007-06-14
}}</ref> The first written usage of the word occurs in a [[he
rbal]] dated 1373, but there is a 1363 document in which the word "dandelion" was used as a proper name (Willelmus Dawndelyon).
In Norwegian, the ''dandelion'' is called ''Løvetann'', which is also translated as "lion's tooth", also ''Löwenzahn'' ("lions' tooth") in German. In modern French the plant is called ''pissenlit'', which means "urinate in bed", apparently referring to its [[diuretic]] properties. Likewise, "pissabeds" is an English folkname for this plant, and "piscialletto" is one of its folknames in [[Italian language|Italian]] (with "dente di leone", meaning "lion's tooth"). Similarly in Spanish, it is known as the "meacamas", but also commonly "diente de león". In Portuguese, its common name is "dente-de-leão" meaning also "lion's tooth". In Turkish the dandelion is called "karahindiba" meaning "black endive". Hungarian names are ''kutyatej'' ("dog milk", referring to the white sap found in the stem) and ''gyermekláncfű'' ("child's chain grass", referring to the habit of children to pick dandelions, remove the flowers, and make links out of the stems by "plugging" the narrow top end of the stem into the wider bottom end).
==Selected species==
* ''[[Taraxacum officinale]]'' (syn. ''T. officinale subsp. vulgare''), Common Dandelion. Found in many forms, but differs at least from the following species:
* ''[[Taraxacum albidum]]'', a white-flowering [[Japan]]ese dandelion.
* ''[[Taraxacum japonicum]]'', Japanese dandelion. No ring of smallish, downward-turned leaves under the flowerhead.
* ''[[Taraxacum laevigatum]]'' (syn. ''T. erythrospermum''), Red-seeded Dandelion; achenes reddish brown and leaves deeply cut throughout length. Inner bracts' tips are hooded.
==Seed development and genetics==
As aforementioned, the taxonomical situation of the genus is quite complex, mainly because many dandelions are genetically [[polyploidy|triploid]]. An odd number of [[chromosomes]] usually is associated with [[infertility|sterility]], but dandelions with this [[karyotype]] can reproduce without [[fertilization]], a process called [[apomixis]]<ref>http://www.talkorigins.org/faqs/comdesc/section2.html#vestiges</ref>. In these individuals [[flower]]s are useless [[vestigial]] structures, although they may still produce a small percentage of fertile [[pollen]], keeping some genetic contact with sexual individuals. Diploid dandelions develop seeds after cross-[[pollination]] and are self-incompatible. In most zones of southern [[Europe]] and [[Asia]], dandelion populations are sexual or mixed sexual-apomictic, while in northern countries only triploid and tetraploid apomicts are present, as is in the zones where it is not native. This seems to be linked to higher temperatures, survival of pre-glacial populations and human impact, but the subject is still being studied.
There are usually 54 to 172 seeds produced per head, but a single plant can produce more than 2000 seeds a year. It has been estimated that more than 97 000 000 seeds/[[hectare]] could be produced every year by a dense stand of dandelions.
==Dandelion Snow==
After pollination, the dandelion flower dries out for about 10 days and then the seed-bearing parachutes expand and lift out of the dried flower head. The dried part of the flower drops off and the parachute ball opens into a full sphere. The parachute drops off when the seed strikes an obstacle. Often dandelions can be observed growing in a crevice near a wall, because the blowing fruits hit the wall and the feathery pappi drop off, sending the dandelion seeds to the base of the obstacle where they germinate. After the seed is released, the parachutes lose their feathered structure and take on a fuzzy, cotton-like appearance, often called "dandelion snow."
==Uses==
[[Image:Dandelion Blackwell 0136.jpg|thumb|right|The dandelion's [[taproot]], shown in this drawing, makes this plant very difficult to uproot; the top of the plant breaks away, but the root stays in the ground and can sprout again.]]
While the dandelion is considered a [[weed]] by many gardeners and lawn owners, the plant does have seve
ral [[culinary]] and [[herb|medicinal]] uses. Dandelions are grown commercially at a small scale as a [[leaf vegetable]]. The plant can be eaten cooked or raw in various forms, such as in [[soup]] or [[salad]]. They are probably closest in character to [[Mustard plant|mustard]] greens. Usually the young leaves and unopened buds are eaten raw in salads, while older leaves are cooked. Raw leaves have a slightly bitter taste. Dandelion salad is often accompanied with hard boiled [[egg (food)|egg]]s. The leaves are high in [[vitamin A]], [[vitamin C]] and [[iron]], carrying more iron and [[calcium]] than [[spinach]].<ref>[http://www.wildmanstevebrill.com/Plants.Folder/Dandelion.html An article about dandelion nutrition.]</ref>
Dandelion flowers can be used to make dandelion [[wine]]. The recipe usually contains [[citrus fruit]]. Another recipe using the plant is dandelion flower jam. Ground roasted dandelion root can be used as a [[coffee]] substitute. Drunk before meals, it is believed to stimulate digestive functions. Sold in most health food stores, often in a mixture, it is considered an excellent cleansing tonic for the liver.
{{main|Medicinal properties of dandelion}}
Dandelion root is a registered drug in [[Canada]], sold as a [[diuretic]]. Dandelions are so potent in this effect, that children have been known to wet the bed the night after skin contact from playing with them.<ref name="CBC"/> A leaf decoction can be drunk to "purify the blood", for the treatment of anemia, jaundice, and also for nervousness. The milky latex has been used as a mosquito repellent; the milk is also applied to warts, helping get rid of them without damaging the surrounding skin. A dye can also be obtained from the roots of the plant. A new mixture of roasted roots is sold as a product called DandyBlend which tastes like coffee after the [[inulin]] in the dandelion is roasted.
"[[Dandelion and burdock|Dandelion and Burdock]]" is a soft drink that has long been popular in the [[United Kingdom]] with authentic recipes sold by health food shops. It is unclear whether cheaper supermarket versions actually contain either plant.
This plant also is useful in farming, because its deep, strong roots break up [[hardpan]].
===Antioxidant properties===
Dandelion contains luteolin, an [[antioxidant]], and has demonstrated antioxidant properties without [[cytotoxicity]].<ref>Chun Hu and David D. Kitts. Food, Nutrition and Health, Faculty of Agricultural Sciences, University of British Columbia, Vancouver, BC, Canada. October 2004. Luteolin and luteolin-7-O-glucoside from dandelion flower suppress iNOS and COX-2 in RAW264.7 cells. Springer Netherlands. '''245''':1-2(107-113). </ref>[http://www.springerlink.com/content/qg16p71737602150/]
===Caffeic acid and carcinogenicity===
[[Caffeic acid]] is a secondary plant metabolite produced in dandelion, [[yarrow]], [[horsetail]] and [[whitethorn]]. Despite its name, it is totally unrelated to [[caffeine]]. Recent studies have revealed this acid may be [[carcinogenic]]. Caffeic acid was tested for carcinogenicity by oral administration in mice, it produced renal cell [[adenoma]]s in females, and a high incidence of renal tubular cell [[hyperplasia]] in animals of each sex.<ref>''Caffeic acid phenethyl ester is a potent and specific inhibitor of activation of nuclear transcription factor NF-kappa B.'', Natarajan K, Singh S, Burke TR Jr, Grunberger D, Aggarwal BB., Proc. Natl. Acad. Sci. U S A., 1996 Aug 20;93(17):9090-5.</ref> However, more recent research shows that [[bacteria]] present in the rats' guts may alter the formation of [[metabolite]]s of caffeic acid. [http://www.pnas.org/cgi/content/abstract/69/6/1413] and [http://jn.nutrition.org/cgi/content/full/133/6/1853] Also, there have been no known ill-effects of caffeic acid in humans.
==False dandelions==
Dandelions are so similar to [[catsear]]s (''Hypochoeris'') that catsears are also known as "false dandelions." Both plants carry similar flowers which form into windborne seeds. However, catsear flowering stems are forked and solid, whereas da
ndelions possess unforked stems that are hollow. Both plants have a rosette of leaves and a central taproot. However, the leaves of dandelions are jagged in appearance, whereas those of catsear are more lobe-shaped and hairy.
Other plants with similar flowers include [[hawkweed]]s (''Hieracium'') and [[crepis|hawksbeard]]s (''Crepis''). These are both readily distinguished by their branched flowering stems.
<div style="clear: both"></div>
==See also==
* [[List of beneficial weeds]]
* [[List of companion plants]]
==References and external links==
{{commonscat|Taraxacum}}
* Richards, A. J. 1972. The ''Taraxacum'' flora of the British Isles. ''Watsonia'' 9 (supplement): 1-141.
* Gail, Peter. ''The Dandelion Celebration: A Guide to Unexpected Cuisine''. Cleveland, Ohio: Goosefoot Acres Press, 1994. ISBN 1-879863-51-0.
*[http://en.wikibooks.org/wiki/Transwiki:How_to_cook_dandelions How to cook dandelions] ~ at ''Wikibooks''
* [http://fxcuisine.com/default.asp?Display=78 Dandelion Syrup - step-by-step illustrated recipe in English]
*[http://fohn.net/dandelion-pictures/ Dandelion Poetry, Folklore, Literature, and Pictures]
*[http://www.pfaf.org/database/plants.php?Taraxacum+officinale&CAN=WIKIPEDIA Dandelion at Plants For A Future]
*[http://ipcm.wisc.edu/uw_weeds/extension/articles/dandelion.htm a university of Wisconsin article on dandelions]
*{{cite web|title=SpringerLink|work=Chun Hu and David D. Kitts. Food, Nutrition and Health, Faculty of Agricultural Sciences, University of British Columbia, Vancouver, BC, Canada. October 2004. Luteolin and luteolin-7-O-glucoside from dandelion flower suppress iNOS and COX-2 in RAW264.7 cells. Springer Netherlands. '''245''':1-2(107-113)
|url=http://www.springerlink.com/content/qg16p71737602150/}}
<references/>
[[Category:Asteraceae]]
[[Category:Herbs]]
[[Category:Invasive species]]
[[Category:Leaf vegetables]]
[[Category:Lawn weeds]]
[[Category:Medicinal plants]]
[[Category:Flora of Greenland]]