Lactuca serriola | |
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Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Asterids |
Order: | Asterales |
Family: | Asteraceae |
Genus: | Lactuca |
Species: | L. serriola |
Binomial name | |
Lactuca serriola | |
Synonyms [1] | |
Synonymy
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Lactuca serriola, also called prickly lettuce, [2] milk thistle [2] (not to be confused with Silybum marianum , also called milk thistle), compass plant, [2] and scarole, [2] is an annual or biennial plant in the tribe Cichorieae within the family Asteraceae. It has a slightly fetid odor and is commonly considered a weed of orchards, roadsides and field crops. [3] It is the closest wild relative of cultivated lettuce ( Lactuca sativa L.).
Lactuca serriola is known as the compass plant because in the sun the upper leaves twist round to hold their margins upright. [4]
Lactuca serriola is native to Europe, Asia, and north Africa, and has become naturalized elsewhere. [2] [5] [6] [7] [8] [9]
Lactuca serriola has a spineless reddish stem, containing a milky latex, growing up to 2 metres (6 ft 7 in). [10]
The leaves get progressively smaller as they reach its top. They are oblong or lanceolate, often pinnately lobed and (especially for the lower leaves), waxy grey green. Fine spines are present along the veins and leaf edges. The undersides have whitish veins. They emit latex when cut.
The flower heads are 1–1.5 cm (1⁄2–1⁄2 in) wide, [10] pale yellow, often tinged purple, with 12–20 ray flowers but no disc flowers. The bracts are also often tinged purple. It flowers from July until September in the northern hemisphere. The achenes are grey, tipped with bristles. The pappus is white with equal length hairs. [5] [11]
Similar to Mycelis muralis but showing more than 5 florets.
It can cause pulmonary emphysema in cattle feeding exclusively on the plant. [12]
Lactuca serriola can be eaten as a salad, although it has something of a bitter taste. Young leaves can be eaten raw or cooked. [13] Older leaves can be steamed. [14] While unsubstantial, its roots have been used as a coffee substitute. [15]
Its presence in some ancient deposits has been linked more to its soporific properties which might suggest ritual use. The Ancient Greeks also believed its pungent juice to be a remedy against eye ulcers and Pythagoreans called the lettuce eunuch because it caused urination and relaxed sexual desire. [16] Following its accidental introduction to North America, the Navajo began to use the plant as a ceremonial emetic. [17] In the island of Crete in Greece the leaves and the tender shoots of a variety called maroula (μαρούλα) or agriomaroulo (αγριομάρουλο) are eaten boiled. [18] It is used by a growing number of Jews and Samaritans as the Maror (bitter herb) on Pesach.[ citation needed ]
Lactuca serriola contains lactucarium, which is the milky sap (white latex) that flows through the stem of the plant. It is used as a medicinal herb when air-dried. Although the standard definition of lactucarium requires its production from Lactuca virosa , it was recognized that smaller quantities of lactucarium could be produced in a similar way from Lactuca sativa and Lactuca canadensis var. elongata, and even that lettuce-opium obtained from Lactuca serriola or Lactuca quercina was of superior quality. [19] [20] [21]
The Egyptian god Min is associated with this species of lettuce. Also, archaeobotanical evidence in Greek archaeological contexts is scanty, although uncarbonised seeds have been retrieved from a 7th-century BC deposit in a sanctuary of Hera on Samos. It is also described by Theophrastus. In mythology, Aphrodite is said to have laid Adonis in a lettuce bed, leading to the vegetable's association with food for the dead. [22]
Lactuca serriola is the wild progenitor of cultivated lettuce ( Lactuca sativa ), and can be affected by lettuce downy mildew, one of the most serious diseases of lettuce. [23] L. serriola has shown resistance to the plant pathogen Bremia lactucae , the cause of the disease. [23] This pathogen is able to undergo sexual reproduction, and once virulent strains have been produced, can undergo rapid asexual reproductive cycles. [24] As a result, there are many strains, which vary in virulence. [24]
Resistance to Bremia lactucae in Lactuca serriola is due to Dm genes, or single dominant genes. [24] Nine of the dominant genes that confer resistance are Dml, Dm, Dm3, Dm6, Dml4, Dml5, DmlO,Dm5/8, Dm10, Dm4, Dm7, Dm11, and Dm13. [23] These genes are mapped in four linkage groups, so the genes within each group will be more likely to be inherited together. [23] Lactuca serriola and B. lactucae have a gene-for-gene relationship, [25] meaning that each resistance gene in the plant is associated with a specific gene in the pathogen, with avirulence being dominant to virulence. [23] The possible combinations of these Dm genes can provide the plant with resistance to multiple strains of Bremia lactucae. [23]
Testing for the presence of new resistance factors is conducted by screening samples of L. serriola with various isolates of B. lactucae. [23] Samples of L. serriola can be found around the world with genetic diversity between populations regarding the Dm genes. [26] This genetic diversity is considered a resource for lettuce breeding because it provides a greater variety of genes to be used in response to new strains of B. lactucae, which continually emerge. [23] [26] There is especially high diversity within the Mediterranean area and Southwest Asia, but L. serriola has established populations on all continents and has the most widespread distribution compared to other Lactuca species. [26]
Lettuce is an annual plant of the family Asteraceae. It is most often grown as a leaf vegetable, but sometimes for its stem and seeds. Lettuce is most often used for salads, although it is also seen in other kinds of food, such as soups, sandwiches and wraps; it can also be grilled. One variety, celtuce, is grown for its stems, which are eaten either raw or cooked. In addition to its main use as a leafy green, it has also gathered religious and medicinal significance over centuries of human consumption. Europe and North America originally dominated the market for lettuce, but by the late 20th century the consumption of lettuce had spread throughout the world. As of 2021, world production of lettuce and chicory was 27 million tonnes, 53 percent of which came from China.
Lactuca, commonly known as lettuce, is a genus of flowering plants in the family Asteraceae. The genus includes at least 50 species, distributed worldwide, but mainly in temperate Eurasia.
Lactucarium is the milky fluid secreted by several species of lettuce, especially Lactuca virosa, usually from the base of the stems. It is known as lettuce opium because of its sedative and analgesic properties. It has also been reported to promote a mild sensation of euphoria. Because it is a latex, lactucarium physically resembles opium, in that it is excreted as a white fluid and can be reduced to a thick smokable solid.
Papaver somniferum, commonly known as the opium poppy or breadseed poppy, is a species of flowering plant in the family Papaveraceae. It is the species of plant from which both opium and poppy seeds are derived and is also a valuable ornamental plant grown in gardens. Its native range was east of the Mediterranean Sea, but now is obscured by ancient introductions and cultivation, being naturalized across much of Europe and Asia.
Leaf vegetables, also called leafy greens, pot herbs, vegetable greens, or simply greens, are plant leaves eaten as a vegetable, sometimes accompanied by tender petioles and shoots. Leaf vegetables eaten raw in a salad can be called salad greens.
Capsella bursa-pastoris, known as shepherd's purse because of its triangular flat fruits, which are purse-like, is a small annual and ruderal flowering plant in the mustard family (Brassicaceae). It is native to eastern Europe and Asia minor, but is naturalized and considered a common weed in many parts of the world, especially in colder climates, including British Isles, where it is regarded as an archaeophyte, North America and China, but also in the Mediterranean and North Africa. C. bursa-pastoris is the second-most prolific wild plant in the world, and is common on cultivated ground and waysides and meadows.
Lactuca virosa is a plant in the Lactuca (lettuce) genus, often ingested for its mild analgesic and sedative effects. It is related to common lettuce, and is often called wild lettuce, bitter lettuce, laitue vireuse, opium lettuce, poisonous lettuce, tall lettuce, great lettuce or rakutu-karyumu-so.
Wild lettuce is a common name for several lactucarium-containing plants related to lettuce. The name most often refers to Lactuca virosa, though it may also refer to:
Peronosporaceae are a family of water moulds that contains 21 genera, comprising more than 600 species. Most of them are called downy mildews.
The gene-for-gene relationship is a concept in plant pathology that plants and their diseases each have single genes that interact with each other during an infection. It was proposed by Harold Henry Flor who was working with rust (Melampsora lini) of flax (Linum usitatissimum). Flor showed that the inheritance of both resistance in the host and parasite ability to cause disease is controlled by pairs of matching genes. One is a plant gene called the resistance (R) gene. The other is a parasite gene called the avirulence (Avr) gene. Plants producing a specific R gene product are resistant towards a pathogen that produces the corresponding Avr gene product. Gene-for-gene relationships are a widespread and very important aspect of plant disease resistance. Another example can be seen with Lactuca serriola versus Bremia lactucae.
Bremia lactucae is a plant pathogen. This microorganism causes a disease of lettuce denominated as downy mildew. Some other strains can be found on 36 genera of Asteraceae including Senecio and Sonchus. Experiments using sporangia from hosts do not infect lettuce and it is concluded that the fungus exists as a quantity of host-specific strains. Wild species, such as Lactuca serriola, or varieties of Lactuca can hold strains that infect lettuce, but these pathogens are not sufficiently common to seriously infect the plant.
Plasmopara halstedii is a plant pathogen infecting sunflowers. The species is one of many pathogens commonly referred to as downy mildew. P. halstedii originated in North America.
Lactuca canadensis is a species of wild lettuce known by the common names Canada lettuce, Canada wild lettuce, and tall lettuce. Its true native range is not clear, but it is considered to be a native of the eastern and central parts of North America. It naturalized in the western part of the continent as well as in Eurasia.
Lactuca saligna is a species of wild lettuce known by the common name willowleaf lettuce, and least lettuce. It is native to Eurasia but it grows in many other places as an introduced species, including much of North America.
Lactuca muralis, the wall lettuce, is a perennial flowering plant in the tribe Cichorieae within the family Asteraceae, also referred to as Mycelis muralis.
Nabalus is a genus of Asian and North American flowering plants in the tribe Cichorieae within the family Asteraceae.
China is the world leader in lettuce production, producing half of the world's lettuce. Stem lettuce is grown in the country and the stems are prepared as a cooked vegetable. According to estimates given by the Food and Agriculture Organization (FAO) in 2006, China produced around 11,005,000 metric tonnes of lettuce on 500,250 hectares of land. In 2010, the FAO reported that some 12,574,500 tonnes of lettuce were produced during that year. Taiwan is also a producer of good quality head lettuce, which is an export commodity.
Lactuca floridana, commonly known as woodland lettuce, Florida lettuce, or false lettuce is a North American species of wild lettuce. It is native across much of central Canada and the eastern and central United States.
Lactuca quercina is a species of wild lettuce native to Europe and Asia. It is an annual or biennial herb in the tribe Cichorieae within the family Asteraceae growing from a taproot to maximum heights of 50–200 cm (19.5–78.5 in) or more.
Lactuca aculeata is a species of wild lettuce native to Anatolia, the Levant, Iraq and Iran. A very prickly plant, it is closely related to Lactuca serriola and Lactuca sativa, and can readily interbreed with them. It is possible that Lactuca aculeata contributed to the gene pool of cultivated lettuce.
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: CS1 maint: multiple names: authors list (link)Media related to Lactuca serriola at Wikimedia Commons