Taraxacum officinale | |
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Common dandelion [1] | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Asterids |
Order: | Asterales |
Family: | Asteraceae |
Genus: | Taraxacum |
Species: | T. officinale |
Binomial name | |
Taraxacum officinale | |
Synonyms [4] [5] | |
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Taraxacum officinale, the dandelion or commondandelion, [6] is a herbaceous perennial flowering plant in the daisy family, Asteraceae. The common dandelion is well known for its yellow flower heads that turn into round balls of many silver-tufted fruits that disperse in the wind. These balls are called "clocks" in both British and American English. [7] [8] [9] [10] The name "blowball" is also used. [11]
The common dandelion grows in temperate regions of the world in areas with moist soils. They are very hardy plants, able to grow in a variety of environments, and are tolerant of crowding, extremes of temperature, and low moisture. [12] As a result of this hardiness, in addition to its ability to rapidly propagate itself, the dandelion has become established over a wide range via human activity, originally being native to Eurasia, but can also be found across the Americas, southern Africa, India, Australia and New Zealand as a result of incidental or deliberate introductions.
It is most often considered a weed, especially in lawns and along roadsides, but the leaves, flowers, and roots are sometimes used as food and in herbal medicine.
Taraxacum officinale grows from (generally unbranched) taproots and produces several hollow, leafless flower stems [13] : 470 that are typically 5–40 centimetres (2–15+3⁄4 inches) tall, but sometimes up to 70 cm (28 in) tall. The stems can be tinted purplish, they are upright or lax, and produce flower heads that are held as tall or taller than the foliage. The foliage may be upright-growing or horizontally spreading; the leaves have petioles that are either unwinged or narrowly winged. The stems can be glabrous or sparsely covered with short hairs. Plants have milky latex and the leaves are all basal; each flowering stem lacks bracts and has one single flower head. The yellow flower heads lack receptacle bracts and all the flowers, which are called florets, are ligulate and bisexual. In many lineages, fruits are mostly produced by apomixis, [14] notwithstanding the flowers are visited by many types of insects. [15]
The leaves are 5–45 cm (2–17+3⁄4 in) long and 1–10 cm (1⁄2–4 in) wide, and are oblanceolate, oblong, or obovate in shape, with the bases gradually narrowing to the petiole. The leaf margins are typically shallowly lobed to deeply lobed and often lacerate or toothed with sharp or dull teeth. [14]
The calyculi (the cuplike bracts that hold the florets) are composed of 12 to 18 segments: each segment is reflexed and sometimes glaucous. The lanceolate shaped bractlets are in two series, with the apices acuminate in shape. The 14–25 millimetres (1⁄2–1 in) wide involucres are green to dark green or brownish-green, with the tips dark gray or purplish. The florets number 40 to over 100 per head, having corollas that are yellow or orange-yellow in color.
The fruits, called cypselae, [16] range in color from olive-green or olive-brown to straw-colored to grayish, they are oblanceoloid in shape and 2–3 mm (1⁄16–1⁄8 in) long with slender beaks. The fruits have 4 to 12 ribs that have sharp edges. The silky pappi, which form the parachutes, are white to silver-white in color and around 6 mm wide. Plants typically have 24 or 40 pairs of chromosomes, while some have 16 or 32 pairs. [17]
Taraxalisin | |
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Identifiers | |
EC no. | ? |
CAS no. | 217442-60-9 |
Taraxalisin is a serine proteinase found in the latex of dandelion roots. [18] Rudenskaya et al. (1998) found that taraxalisin hydrolyzes a chromogenic peptide substrate Glp-Ala-Ala-Leu-pNA optimally at pH 8.0. [19] Maximal activity of the proteinase in the roots is attained in April, at the beginning of plant development after the winter period. [19]
Carl Linnaeus named the species Leontodon taraxacum in 1753. The current genus name Taraxacum derives possibly from the Arabic Tharakhchakon, [14] or from the Greek Tarraxos. [20] The specific name officinalis refers to its value as a medicinal herb, and is derived from the word opificina, later officina, meaning a workshop or pharmacy. [21]
The taxonomy of the genus Taraxacum is complicated by apomictic and polyploid lineages, [22] [23] and the taxonomy and nomenclatural situation of T. officinale is not yet fully resolved. [17] The taxonomy of this genus has been complicated by the recognition of numerous species, [24] subspecies and microspecies. For example, Rothmaler's flora of Germany recognizes roughly 70 microspecies. [25]
T. officinale has a fossil record that goes back to glacial and interglacial times in Europe. [26]
The plants introduced to North America, originally as a food crop, are triploids that mainly reproduce by obligate gametophytic apomixis [17] [27] Though sexual dandelion plants are known in North America, almost all are clones that produce genetically identical seeds through apomixis. [28] Some authorities recognize three subspecies of Taraxacum officinale, including: [29] [30]
Two of them have been introduced and established in Alaska and the third (subsp. ceratophorum) is native there. [34]
Taraxacum officinale L. (dandelion) is a vigorous weed in Europe with diploid sexual populations in the southern regions and partially overlapping populations of diploid sexuals and triploid or tetraploid apomicts in the central and northern regions.
These European dandelions can be divided into two groups. The first group reproduces sexually, as do most seed plants. This group consists of dandelions that have a diploid set of chromosomes, and are sexually self-incompatible. Sexual reproduction involves a reduction of the somatic chromosome number by meiosis followed by a restoration of the somatic chromosome number by fertilization. Diploid dandelions have eight pairs of chromosomes, and meiosis is regular with normal pairing of homologous chromosomes at the metaphase I stage of meiosis. [35]
The second group consists of polyploid (mostly triploid) apomicts, meaning that both a viable embryo as well as a functional endosperm is formed without prior fertilization. In contrast to the sexual diploids, the pairing of chromosomes at metaphase I in triploid apomicts is strongly reduced. However pairing is still sufficient to allow some recombination between homologous chromosomes. [35]
Taraxacum is derived from the Arabic word tarakhshagog (or tarakhshaqūn) for a bitter herb. [36] It may be related to the Greek word ταρασσω (tarasso) meaning to disturb. [36] [ verification needed ]
The Latin specific epithet officinale refers to the Latin word for 'medicinal' or 'of the apothecaries'. [37]
T. officinale has many English common names (some of which are no longer in use), including blowball, lion's-tooth, cankerwort, milk-witch, yellow-gowan, Irish daisy, monks-head, priest's-crown and puff-ball; [38] other common names include, faceclock, pee-a-bed, wet-a-bed, [39] swine's snout, [40] white endive, and wild endive. [41]
The common name dandelion comes from the French dent de lion, or "lion's tooth", in reference to the plant's jagged-edged leaves. [20] "Pee-a-bed" and "wet-a-bed" reflect the modern French term for the plant, pissenlit. This name and all those that imply ramped-up urine production refer to T. officinale's well-known diuretic properties. [42]
Taraxacum officinale is native to Europe and Asia, [43] and was originally imported to America as a food crop. [44] It is now naturalized throughout North America, southern Africa, South America, New Zealand, Australia, and India. It occurs in all 50 states of the US and most Canadian provinces. [34]
The plant grows in temperate regions of the world in lawns, on roadsides, disturbed banks, shores of waterways, and other areas with moist soils.
The plant is coveted by collectors in regions where the plant is trickier to grow such as the tropics, where people would often resort to smuggling seeds from overseas. [45]
Taraxacum officinale was evaluated in 2013 by the IUCN as "Least Concern" due to a large and stable population. [2] It was similarly evaluated by NatureServe in 2016 as "Globally Secure", G5. [3]
It is considered a noxious weed in some jurisdictions, [46] and is considered to be a nuisance in residential and recreational lawns in North America. [47] It is also an important weed in agriculture and causes significant economic damage because of its infestation in many crops worldwide. [46]
T. officinale can serve as an indicator plant for soil potassium and calcium, as the plant favours soils with relatively low concentrations of calcium, but favours soils with relatively high concentrations of potassium. [48]
The dandelion is a common colonizer of disturbed habitats, both from wind blown seeds and seed germination from the seed bank. [49] The seeds remain viable in the seed bank for many years, with one study showing germination after nine years. This species is a somewhat prolific seed producer, with 54 to 172 seeds produced per head, and a single plant can produce more than 5,000 seeds a year. It is estimated that more than 97,000,000 seeds/hectare could be produced yearly by a dense stand of dandelions. [50] When released, the seeds can be spread by the wind up to several hundred meters from their source. The seeds are also a common contaminant in crop and forage seeds. The plants are adaptable to most soils and the seeds are not dependent on cold temperatures before they will germinate but they need to be within the top 2.5 cm (1 in) of soil. [34] Dandelions can also regenerate themselves from fragments of taproot. [51]
T. officinale is food for the caterpillars of several Lepidoptera (butterflies and moths), such as the tortrix moth Celypha rufana . See also List of Lepidoptera that feed on dandelions.
Even though dandelion pollen is of poor nutritional quality for honey bees, they readily consume it, and it can be an important source of nutritional diversity in heavily managed monocultures such as that of blueberries, [52] [53] or in early spring, as one of the first flowers to bloom. [54] Honey bees have not been shown to lower their pollination activity on nearby fruit crops when foraging on dandelions. [55]
While not in bloom, this species is sometimes confused with others, such as Chondrilla juncea , that have similar basal rosettes of foliage. [56] Another plant, sometimes referred to as fall dandelion, is very similar to dandelion, but produces "yellow fields" later. Its blooms resemble some of the species of Sonchus , but are larger. [57]
Dandelion thrives in conditions of elevated carbon dioxide, growing to a higher biomass and producing a larger number of viable seeds. Therefore, it is anticipated that dandelion will become more competitive and widespread as atmospheric carbon dioxide levels increase. [28]
Nutritional value per 100 g (3.5 oz) | |||||||||||||||||||||||||||||||||||||||||||||||||||
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Energy | 188 kJ (45 kcal) | ||||||||||||||||||||||||||||||||||||||||||||||||||
9.2 g | |||||||||||||||||||||||||||||||||||||||||||||||||||
Sugars | 0.71 g | ||||||||||||||||||||||||||||||||||||||||||||||||||
Dietary fiber | 3.5 g | ||||||||||||||||||||||||||||||||||||||||||||||||||
0.7 g | |||||||||||||||||||||||||||||||||||||||||||||||||||
2.7 g | |||||||||||||||||||||||||||||||||||||||||||||||||||
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Other constituents | Quantity | ||||||||||||||||||||||||||||||||||||||||||||||||||
Water | 85.6 g | ||||||||||||||||||||||||||||||||||||||||||||||||||
†Percentages estimated using US recommendations for adults, [58] except for potassium, which is estimated based on expert recommendation from the National Academies. [59] |
The plant has several culinary uses: the flowers are used to make dandelion wine, [60] the greens are used in salads, the roots have been used to make a coffee substitute (when baked and ground into powder) and the plant was used by Native Americans as a food and medicine. [61]
Dandelions are harvested from the wild or grown 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 vitamins A and C, as well as iron, phosphorus, and potassium. [62]
Dandelion flowers can be used to make dandelion wine, for which there are many recipes. [63] Most of these are more accurately described as "dandelion-flavored wine," as some other sort of fermented juice or extract serves as the main ingredient. [64] It has also been used in a saison ale called Pissenlit (the French word for dandelion, literally meaning "wet the bed") made by Brasserie Fantôme in Belgium. Dandelion and burdock is a soft drink that has long been popular in the United Kingdom.
Another recipe using the plant is dandelion flower jam. In Silesia and other parts of Poland and the world, dandelion flowers are used to make a honey substitute syrup with added lemon (so-called May-honey). Ground roasted dandelion root can be used as a non-caffeinated coffee substitute. [65]
T. officinale's diuretic properties - believed to be a result of the plant’s high potassium content [66] - have been well described. The leaves of the common dandelion have been used as a diuretic in traditional Chinese medicine for approximately 2,000 years, with other regions of the world using the plant in the same way; in French, a common name for T. officinale is pissenlit, 'a colorful description of its diuretic activity.' A study conducted in 2009 noted 'promising' results regarding these diuretic properties, but that further studies would need to be conducted into the plant's efficacy. [67]
Dandelion has been used in traditional medicine in Europe, North America, and China. [68]
Since asexually-reproducing dandelions produce genetically identical offspring, they are often useful as subjects for scientific research. For example, dandelions are used in studies where genetic differences between subjects need to be minimized. [69]
Because of its worldwide distribution, familiarity, and presence in a wide variety of folkloric traditions, the dandelion has been highlighted as a valuable tool for educators seeking to help children of varying cultural and ethnic backgrounds connect to science through ethnobotany. [70]
Yellow dye colors can be obtained from the flowers but little color can be obtained from the roots of the plant. [71] The latex can be used as a kind of glue. [72]
Cultures worldwide tell stories about the dandelion and have culinary and medicinal uses for it. A Native American folktale tells the story of a golden haired girl who attracted the fancy of the South Wind. The South Wind was too lazy to pursue her, until one day he realized she had grown old and her hair had turned white. Supposedly, when the South Wind sighs over the loss of his chance to pursue the golden-haired girl, his breath sends the white-haired dandelion seeds scattering to propagate more golden-haired daughters. [70]
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the full set of genes of their single parent and thus the newly created individual is genetically and physically similar to the parent or an exact clone of the parent. Asexual reproduction is the primary form of reproduction for single-celled organisms such as archaea and bacteria. Many eukaryotic organisms including plants, animals, and fungi can also reproduce asexually. In vertebrates, the most common form of asexual reproduction is parthenogenesis, which is typically used as an alternative to sexual reproduction in times when reproductive opportunities are limited. Some monitor lizards, including Komodo dragons, can reproduce asexually.
Ploidy is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Here sets of chromosomes refers to the number of maternal and paternal chromosome copies, respectively, in each homologous chromosome pair—the form in which chromosomes naturally exist. Somatic cells, tissues, and individual organisms can be described according to the number of sets of chromosomes present : monoploid, diploid, triploid, tetraploid, pentaploid, hexaploid, heptaploid or septaploid, etc. The generic term polyploid is often used to describe cells with three or more sets of chromosomes.
Ginger is a flowering plant whose rhizome, ginger root or ginger, is widely used as a spice and a folk medicine. It is an herbaceous perennial that grows annual pseudostems about one meter tall, bearing narrow leaf blades. The inflorescences bear flowers having pale yellow petals with purple edges, and arise directly from the rhizome on separate shoots.
Polyploidy is a condition in which the cells of an organism have more than two paired sets of (homologous) chromosomes. Most species whose cells have nuclei (eukaryotes) are diploid, meaning they have two complete sets of chromosomes, one from each of two parents; each set contains the same number of chromosomes, and the chromosomes are joined in pairs of homologous chromosomes. However, some organisms are polyploid. Polyploidy is especially common in plants. Most eukaryotes have diploid somatic cells, but produce haploid gametes by meiosis. A monoploid has only one set of chromosomes, and the term is usually only applied to cells or organisms that are normally diploid. Males of bees and other Hymenoptera, for example, are monoploid. Unlike animals, plants and multicellular algae have life cycles with two alternating multicellular generations. The gametophyte generation is haploid, and produces gametes by mitosis; the sporophyte generation is diploid and produces spores by meiosis.
In botany, apomixis is asexual development of seed or embryo without fertilization. However, other definitions include replacement of the seed by a plantlet or replacement of the flower by bulbils.
Hypericum perforatum, commonly known as St John's wort, is a flowering plant in the family Hypericaceae. It is a perennial plant that grows up to 1 metre tall, with many yellow flowers that have clearly visible black glands around their edges, long stamens, and three pistils. Probably a hybrid between the closely related H. attenuatum and H. maculatum that originated in Siberia, the species is now found worldwide. It is native to temperate regions across Eurasia and North Africa, and has been introduced to East Asia, Australia, New Zealand, and parts of North and South America. In many areas where it is not native, H. perforatum is considered a noxious weed. It densely covers open areas to the exclusion of native plants, and is poor grazing material. As such, methods for biocontrol have been introduced in an attempt to slow or reverse the spread of the species.
Vegetative reproduction is a form of asexual reproduction occurring in plants in which a new plant grows from a fragment or cutting of the parent plant or specialized reproductive structures, which are sometimes called vegetative propagules.
Acorus calamus is a species of flowering plant with psychoactive chemicals. It is a tall wetland monocot of the family Acoraceae, in the genus Acorus. Although used in traditional medicine over centuries to treat digestive disorders and pain, it has no clinical evidence of safety or efficacy and may be toxic if ingested, and so has been commercially banned in the United States.
The endosperm is a tissue produced inside the seeds of most of the flowering plants following double fertilization. It is triploid in most species, which may be auxin-driven. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. This can make endosperm a source of nutrition in animal diet. For example, wheat endosperm is ground into flour for bread, while barley endosperm is the main source of sugars for beer production. Other examples of endosperm that forms the bulk of the edible portion are coconut "meat" and coconut "water", and corn. Some plants, such as certain orchids, lack endosperm in their seeds.
Rosa canina, the dog rose, is a variable climbing, wild rose species native to Europe, northwest Africa, and western Asia.
Crocus sativus, commonly known as saffron crocus or autumn crocus, is a species of flowering plant in the iris family Iridaceae. A cormous autumn-flowering cultivated perennial, unknown in the wild, it is best known for the culinary use of its floral stigmas as the spice saffron. Human cultivation of saffron crocus and the trade and use of saffron have endured for more than 3,500 years and span different cultures, continents, and civilizations.
Crepis, commonly known in some parts of the world as hawksbeard or hawk's-beard, is a genus of annual and perennial flowering plants of the family Asteraceae superficially resembling the dandelion, the most conspicuous difference being that Crepis usually has branching scapes with multiple heads. The genus name Crepis derives from the Greek krepis, meaning "slipper" or "sandal", possibly in reference to the shape of the fruit.
Plant reproduction is the production of new offspring in plants, which can be accomplished by sexual or asexual reproduction. Sexual reproduction produces offspring by the fusion of gametes, resulting in offspring genetically different from either parent. Asexual reproduction produces new individuals without the fusion of gametes, resulting in clonal plants that are genetically identical to the parent plant and each other, unless mutations occur.
Taraxacum californicum, also known as the California dandelion, is an endangered species of dandelion endemic to the San Bernardino Mountains of California. It grows in mountain meadows.
Taraxacum is a large genus of flowering plants in the family Asteraceae, which consists of species commonly known as dandelions. The scientific and hobby study of the genus is known as taraxacology. The genus is native to Eurasia but the two most commonplace species worldwide, T. officinale and T. erythrospermum, were introduced from Europe into North America, where they are an invasive species. Dandelions thrive in temperate regions and can be found in yards, gardens, sides of roads, among crops, and in many other habitats. Both species are edible in their entirety and have a long history of consumption. The common name dandelion is also given to specific members of the genus.
Hypericum androsaemum, the shrubby St. John's wort, is a flowering plant in the family Hypericaceae. Commonly called tutsan or sweet-amber, the species is cultivated as an ornamental plant because of its striking red-tinted foliage, bright yellow petals, and its large clusters of fruit. Cultivars like 'Albury Purple' and 'Golden Tutsan' which have leaves with more pronounced purple and golden coloring, respectively.
Dandelion coffee is a tisane made from the root of the dandelion plant. The roasted dandelion root pieces and the beverage have some resemblance to coffee in appearance and taste, and it is thus commonly considered a coffee substitute.
Pseudogamy refers to aspects of reproduction. It has different meanings in zoology and in botany.
Taraxacum kok-saghyz, often abbreviated as TKS and commonly referred to as the Kazakh dandelion, rubber root, or Russian dandelion, is a species of dandelion native to Kazakhstan, Kyrgyzstan and Uzbekistan, notable for its production of high-quality rubber. T. kok-saghyz was discovered in Kazakhstan in 1932 by Soviet scientists seeking a domestic source of rubber.
Taraxacum ceratophorum, also known as the horned dandelion, is a species of flowering plant within the genus Taraxacum and family Asteraceae. This alpine species has a preference for mountainous habitat, where it can be found growing at elevations up to 3000 meters above sea level. It is native to a large portion of the Northern Hemisphere, inhabiting various countries within Asia, Europe and North America.
Swine's Snout.