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Dandelion
A flowering dandelion
Scientific classification
Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Asterales Family: Asteraceae Tribe: Cichorieae Genus: Taraxacum Cass.
Species
See text Dandelion may refer to: Dandelion, the plant Dandelion, the official flower of the University of Rochester. ... Image File history File linksMetadata Size of this preview: 503 × 599 pixels Full resolution (2112 × 2516 pixel, file size: 2. ... Scientific classification redirects here. ... For other uses, see Plant (disambiguation). ... Classes Magnoliopsida - Dicots Liliopsida - Monocots The flowering plants or angiosperms are the most widespread group of land plants. ... Orders See text. ... Families Alseuosmiaceae Argophyllaceae Asteraceae - Daisies Calyceraceae Campanulaceae (incl. ... Diversity About 1500 genera and 23,000 species Type Genus Aster L. Subfamilies Barnadesioideae Cichorioideae Tribe Arctotidae Tribe Cardueae Tribe Eremothamneae Tribe Lactuceae Tribe Liabeae Tribe Mutisieae Tribe Tarchonantheae Tribe Vernonieae Asteroideae Tribe Anthemideae Tribe Astereae Tribe Calenduleae Tribe Eupatorieae Tribe Gnaphalieae Tribe Helenieae Tribe Heliantheae Tribe Inuleae Tribe Plucheae... Count Alexandre Henri Gabriel de Cassini (1781-1832) was a French botanist and naturalist, who specialised in the sunflower family (Asteraceae) (then known as family Compositae). ...

The common name Dandelion is given to members of the genus Taraxacum, a large genus of flowering plants in the family Asteraceae. In the Asteraceae (formerly Compositae) the 'flowers' are morphologically a composite flower head consisting of many tiny flowers called florets. Dandelions are native to Africa, Asia and Europe, and have been widely introduced elsewhere. Many Taraxacum species produce seeds asexually (apomixis), so that seeds can be produced without pollination that are genetically identical to the parent plant.^[1] For other uses, see Genus (disambiguation). ... Classes Magnoliopsida - Dicots Liliopsida - Monocots The flowering plants or angiosperms are the most widespread group of land plants. ... Diversity About 1500 genera and 23,000 species Type Genus Aster L. Subfamilies Barnadesioideae Cichorioideae Tribe Arctotidae Tribe Cardueae Tribe Eremothamneae Tribe Lactuceae Tribe Liabeae Tribe Mutisieae Tribe Tarchonantheae Tribe Vernonieae Asteroideae Tribe Anthemideae Tribe Astereae Tribe Calenduleae Tribe Eupatorieae Tribe Gnaphalieae Tribe Helenieae Tribe Heliantheae Tribe Inuleae Tribe Plucheae... The term morphology in biology refers to the outward appearance (shape, structure, colour, pattern) of an organism or taxon and its component parts. ... Example of a flower head. ... It has been suggested that Parthenogenesis be merged into this article or section. ... In botany, apomixis is asexual reproduction, without fertilization. ... Carpenter bee with pollen collected from Night-blooming cereus Pollination is an important step in the reproduction of seed plants: the transfer of pollen grains (containing the male gametes, sperm) to the plant carpel of flowering plants, the structure that contains the ovule (which in turn houses the female gamete...

Description

A dandelion clock.

Dandelions are tap-rooted biennial or perennial herbaceous plants, native to temperate areas of the Northern Hemisphere of the Old World. They are commonly known as weeds or ruderals. The genus is taxonomically very complex, with numerous macrospecies, and polyploidy is also common; over 250 apomictic microspecies 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. Image File history File linksMetadata Size of this preview: 800 × 600 pixel Image in higher resolution (3264 × 2448 pixel, file size: 1. ... Image File history File linksMetadata Size of this preview: 800 × 600 pixel Image in higher resolution (3264 × 2448 pixel, file size: 1. ... This article is about the plant root system. ... A Biennial plant is a plant that takes between twelve and twenty-four months to complete its lifecycle. ... Red Valerian, a perennial plant. ... This article is about the plants used in cooking and medicine. ... For the usage in virology, see temperate (virology). ... Northern hemisphere highlighted in yellow. ... For other uses, see Old World (disambiguation). ... A single-species ruderal community of Dittricia viscosa on the railway-side gravel, next to the Petah Tikva-Sgula railway station, Israel. ... For the science of classifying living things, see alpha taxonomy. ... Polyploid (in Greek: πολλαπλόν - multiple) cells or organisms contain more than one copy (ploidy) of their chromosomes. ... This article explains the archipelago in north-western Europe. ...

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, which kills other plants by cutting off their access to sunlight. A bright yellow 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 (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 florets. The flower head matures into a spherical "clock" (also known as "wishies") containing many single-seeded fruits (achenes). Each achene is attached to a pappus of fine hairs, which enable wind-dispersal over long distances. Red clover inflorescence (spike) An inflorescence is a group or cluster of flowers on a branch of a plant. ... Sap exuding (gummosis) from the stem of a koa tree, probably in response to surface damage Sap is the fluid carried in tubules inside a plant, circulating to distribute food and water to various parts of the plant. ... This article is about the typesetting system. ... Wildflowers A flower is the reproductive organ of those plants classified as angiosperms (flowering plants; Division Magnoliophyta). ... An achene is a type of simple dry fruit produced by many species of flowering plants. ...

Dandelions are used as food plants by the larvae of some species of Lepidoptera (butterflies and moths). See List of Lepidoptera that feed on dandelions. Away from their native regions, dandelions have become established in the Americas, Australia and New Zealand and are now common throughout all temperate regions. A larval insect A larva (Latin; plural larvae) is a juvenile form of animal with indirect development, undergoing metamorphosis (for example, insects or amphibians). ... Subdivisions See Taxonomy of Lepidoptera and Lepidopteran diversity. ... For other uses of the term butterfly, see butterfly (disambiguation). ... Lepidopteran on a flower. ... World map showing the Americas CIA political map of the Americas in an equal-area projection The Americas are the lands of the New World, consisting of the continents of North America and South America with their associated islands and regions. ...

History

Dandelions evolved about thirty million years ago in Eurasia[1].

They were used by humans for food and herbalism for much of recorded history.

Origin of the name

The English name dandelion is a corruption of the French dent de lion^[2] meaning lion's tooth, referring to the coarsely-toothed leaves. The names of the plant have the same meaning in several other European languages, such as Italian dente di leone, Spanish diente de león, Portuguese dente-de-leão, Norwegian Løvetann, and German Löwenzahn.
In modern French the plant is named pissenlit, which means "urinate in bed", apparently referring to its diuretic properties. Likewise, "pissabeds" is an English folkname for this plant, piscialletto in Italian and in Spanish it is known as the meacamas.
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).
Lithuanian name kiaulpienė can be translated as "sow Sonchus" (because plant Sonchus that has white sap also in Lithuanian is pienė (from pienas "milk)) or "sow milk". In Finnish it is called 'voikukka' ("butter flower") referring to its buttery colour. In Swedish it is called 'maskros' ("worm rose"), likely referring to it's low status (being mostly considered a weed) despite a fairly pleasant appearance. For other uses, see Lion (disambiguation). ... This illustration shows where some types of diuretics act, and what they do. ... Species Sonchus asper (spiny sow thistle) Sonchus arvensis (field or perennial sow thistle) Sonchus dregeanus Sonchus integrifolius Sonchus nanus Sonchus oleraceus (common sow thistle) Sonchus wilmsii (milk thistle) Sow thistle (less commonly hare thistle or hare lettuce) is the common name for a number of related annual herbs in the...

Seeds

A microscopic view of a pappus from a dandelion clock.

The flower head is surrounded by bracts (sometimes mistakenly called sepals) in two series. The inner bracts 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. 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." While it was probably not developed evolutionarily, Dandelions seeds are often dispersed by young children, who often blow on or kick the clock. Toothed bracts on Rhinanthus minor In botany, a bract is a modified or specialized leaf, from the axil of which a flower or flower stalk arises; or a bract may be any leaf associated with an inflorescence. ... Flower of the Primrose Willowherb (Ludwigia octovalvis) showing petals and sepals A sepal is one member or part of the calyx of a flower. ... Toothed bracts on Rhinanthus minor In botany, a bract is a modified or specialized leaf, from the axil of which a flower or flower stalk arises; or a bract may be any leaf associated with an inflorescence. ...

Seed development and genetics

A microscopic view of a dandelion clock showing the pericarp and the achenes.

As previously mentioned, the taxonomical situation of the genus is quite complex, mainly because many dandelions are genetically triploid. An odd number of chromosomes usually is associated with sterility, but dandelions with this karyotype can reproduce without fertilization, by a process called apomixis.^[3] In these individuals flowers are inefficient 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 outcrossing, or 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. Species Elaeis guineensis Elaeis oleifera The oil palms (Elaeis) coomprise two species of the Arecaceae, or palm family. ... An achene is a type of simple dry fruit produced by many species of flowering plants. ... Polyploidy refers to cells or organisms that contain more than two copies of each of their chromosomes. ... This article is about the biological chromosome. ... Infertility primarily refers to the biological inability of a man or a woman to contribute to conception. ... Karyogram of human male using Giemsa staining. ... Categories: Biology stubs ... In botany, apomixis is asexual reproduction, without fertilization. ... For other uses, see Flower (disambiguation). ... A vestigial organ is an organ whose original function has been lost during evolution. ... SEM image of pollen grains from a variety of common plants: sunflower (Helianthus annuus), morning glory (Ipomoea purpurea), prairie hollyhock (Sidalcea malviflora), oriental lily (Lilium auratum), evening primrose (Oenothera fruticosa), and castor bean (Ricinus communis). ... Diploid (meaning double in Greek) cells have two copies (homologs) of each chromosome (both sex- and non-sex determining chromosomes), usually one from the mother and one from the father. ... Carpenter bee with pollen collected from Night-blooming cereus Pollination is an important step in the reproduction of seed plants: the transfer of pollen grains (containing the male gametes, sperm) to the plant carpel of flowering plants, the structure that contains the ovule (which in turn houses the female gamete... Outcrossing is the practice of introducing unrelated genetic material into a breeding line. ... For other uses, see Europe (disambiguation). ... For other uses, see Asia (disambiguation). ... Polyploid (in Greek: πολλαπλόν - multiple) cells or organisms contain more than one copy (ploidy) of their chromosomes. ...

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. A hectare (symbol ha) is a unit of area, equal to 10 000 square metres, commonly used for measuring land area. ...

Uses

The dandelion's taproot, on left 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.

See also: Medicinal properties of dandelion

While the dandelion is considered a weed by many gardeners and lawn owners, the plant does have several culinary uses, and the specific name officinalis refers to its value as a medicinal herb. Dandelions are grown commercially on a small scale as a leaf vegetable. The leaves (called dandelion greens) can be eaten cooked or raw in various forms, such as in soup or salad. They are probably closest in character to 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 eggs. The leaves are high in vitamin A, vitamin C and iron, carrying more iron and calcium than spinach.^[4] Download high resolution version (753x1140, 242 KB) Wikipedia does not have an article with this exact name. ... Download high resolution version (753x1140, 242 KB) Wikipedia does not have an article with this exact name. ... This article is about the plant root system. ... Dandelions may have medicinal properties. ... Yellow starthistle, a thistle native to southern Europe and the Middle East that is an invasive weed in parts of North America. ... Food from plant sources Food is any substance normally eaten or drunk by living organisms. ... For other uses, see Herb (disambiguation). ... Fresh Swiss chard Fresh water spinach Creamed spinach Steamed kale Leaf vegetables, also called potherbs, greens, or leafy greens, are plant leaves eaten as a vegetable, sometimes accompanied by tender petioles and shoots. ... For other uses, see Soup (disambiguation). ... This article deals with food. ... Species See text. ... Chicken egg (left) and quail eggs (right), the types of egg commonly used as food An egg is a body consisting of an ovum surrounded by layers of membranes and an outer casing of some type, which acts to nourish and protect a developing embryo. ... The structure of retinol, the most common dietary form of vitamin A Vitamin A is an essential human nutrient. ... This article is about the nutrient. ... General Name, symbol, number iron, Fe, 26 Chemical series transition metals Group, period, block 8, 4, d Appearance lustrous metallic with a grayish tinge Standard atomic weight 55. ... For other uses, see Calcium (disambiguation). ... Binomial name Spinacia oleracea L. Percentages are relative to US recommendations for adults. ...

Dandelion flowers can be used to make dandelion wine, for which there are many recipes.^[5] It has also been used in a saison ale called Pissenlit (literally "wet the bed" in French) made by Brasserie Fantôme in Belgium. Another recipe using the plant is dandelion flower jam. Ground roasted dandelion root can be used as a coffee substitute. Dandelion root is a registered drug in Canada, sold principally as a diuretic. A leaf decoction can be drunk to "purify the blood", for the treatment of anemia, jaundice, and also for nervousness. Drunk before meals, dandelion root coffee is claimed to stimulate digestive functions and function as a liver tonic. "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 extracts of either plant. For other uses, see Wine (disambiguation). ... Saison is the name given to pale ales brewed in Wallonia, the French-speaking region of Belgium. ... For other uses, see Ale (disambiguation). ... For other uses, see Coffee (disambiguation). ... This illustration shows where some types of diuretics act, and what they do. ... A decoction is a method of extraction of herbal or plant material, which includes, but is not limited to: Leaves, flowers, stems, roots, bark, and rhizomes. ... Dandelion and burdock is a traditional British soft drink. ...

The milky latex has been used as a mosquito repellent;^[6] the milk is also applied to warts, helping get rid of them without damaging the surrounding skin.^[7]

Yellow or green dye colours can be obtained from the flowers but little colour can be obtained from the roots of the plant.^[8]

A plate of sauteed dandelion greens, with Wehani rice

Wehani rice is a variety of aromatic brown rice developed in the late 20th century by Lundberg Family Farms of Richvale, California, United States. ...

Antioxidant properties

Dandelion contains luteolin, an antioxidant, and has demonstrated antioxidant properties without cytotoxicity.^[9][10] Space-filling model of the antioxidant metabolite glutathione. ... Cytotoxicity is the quality of being poisonous to cells. ...

Caffeic acid and carcinogenicity

Caffeic acid is a secondary plant metabolite produced in dandelion, yarrow, horsetail and whitethorn. Despite its name, it is 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 adenomas in females, and a high incidence of renal tubular cell hyperplasia in animals of each sex.^[11] However, more recent research shows that bacteria present in the rats' guts may alter the formation of metabolites of caffeic acid.^[12][13] There have been no known ill-effects of caffeic acid in humans. Caffeic acid, C9H8O4 is a naturally occurring phenolic compound, (formerly called a carbolic acid), which is found in many fruits, vegetables, and herbs, including coffee, although varying in amounts depending on the plant. ... Binomial name Achillea millefolium L. Yarrow (Achillea millefolium) is a flowering plant in the family Asteraceae, native to the Northern Hemisphere. ... Species The horsetails are vascular plants, comprising 15 species of plants in the genus Equisetum. ... Binomial name Crataegus monogyna Jacq. ... For other uses, see Caffeine (disambiguation). ... In pathology, a carcinogen is any substance or agent that promotes cancer. ... An adenoma is a collection of growths (-oma) of glandular origin. ... Hyperplasia (or hypergenesis) is a general term referring to the proliferation of cells within an organ or tissue beyond that which is ordinarily seen in e. ... Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... A metabolite is the product of metabolism. ...

Bees

Dandelion are an important plant for bees. Not only is the appearance of their flowers used as an indicator that the honey bee season is starting, but they are also an important source of nectar and pollen early in the season.^{[citation needed]}

False dandelions

Macro photo of dandelion seed dispersal.

Dandelions are so similar to catsears (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 dandelions 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. ImageMetadata File history File links Download high resolution version (1024x768, 116 KB) Summary Dandelion seed floaters I, PiccoloNamek, took this photograph. ... ImageMetadata File history File links Download high resolution version (1024x768, 116 KB) Summary Dandelion seed floaters I, PiccoloNamek, took this photograph. ... detail macro 1:1 — a macro photograph. ... Binomial name L. Catsear (Hypochaeris radicata), also known as cats ear or false dandelion, is a perennial, low-lying edible herb often found in lawns. ...

Other plants with similar flowers include hawkweeds (Hieracium) and hawksbeards (Crepis). These are both readily distinguished by their branched flowering stems. Genera Hieracium Pilosella Hawkweed refers to any species in the very large genus Hieracium and its segregate genus Pilosella, in the sunflower family (Asteraceae). ... Hawksbeard is a genus of about 200 annual and perennial flowering plants found in the family Asterales resembling Dandelion, the main differences being that Hawksbeards have multiple flowers per plant as well as branching stems. ...

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 Japanese 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.

Binomial name Taraxacum officinal Taraxacum officinale is a medical herb of the Asteraceae taxon. ...

References and external links

Wikimedia Commons has media related to:

Taraxacum

• Everitt, J.H.; Lonard, R.L., Little, C.R. (2007). Weeds in South Texas and Northern Mexico. Lubbock: Texas Tech University Press.  ISBN 0-89672-614-2
• 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.
• Making Dandelions Palatable by John Kallas of Wild Food Adventures
• How to cook dandelions ~ at Wikibooks
• Dandelion Syrup - step-by-step illustrated recipe in English
• How to Get Rid of Dandelions
• How to Grow Dandelions
• Dandelion Poetry, Folklore, Literature, and Pictures
• Dandelion at Plants For A Future
• a university of Wisconsin article on dandelions
• SpringerLink. 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).

See also

• List of beneficial weeds
• List of companion plants