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Lactuca Serriola
''Lactuca serriola'', also called prickly lettuce, milk thistle (not to be confused with '' Silybum marianum'', also called milk thistle), compass plant, and scarole, 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. It is the closest wild relative of cultivated lettuce ('' Lactuca sativa'' L.). ''Lactuca serriola'' is native to Eurasia and north Africa, and has become naturalized elsewhere. Description ''Lactuca serriola'' has a spineless reddish stem, containing a milky latex, growing up to . 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 wide, pale yellow, often tinged purple, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Linnaeus
Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming organisms. He is known as the "father of modern Taxonomy (biology), taxonomy". Many of his writings were in Latin; his name is rendered in Latin as and, after his 1761 ennoblement, as . Linnaeus was the son of a curate and was born in Råshult, in the countryside of Småland, southern Sweden. He received most of his higher education at Uppsala University and began giving lectures in botany there in 1730. He lived abroad between 1735 and 1738, where he studied and also published the first edition of his ' in the Netherlands. He then returned to Sweden where he became professor of medicine and botany at Uppsala. In the 1740s, he was sent on several journeys through Sweden to find and classify plants and animals. In the 1750s and 1760s, he co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ray Flowers
Asteraceae () is a large family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the order Asterales. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger family is unclear as the quantity of extant species in each family is unknown. The Asteraceae were first described in the year 1740 and given the original name Compositae. The family is commonly known as the aster, daisy, composite, or sunflower family. Most species of Asteraceae are herbaceous plants, and may be annual, biennial, or perennial, but there are also shrubs, vines, and trees. The family has a widespread distribution, from subpolar to tropical regions, in a wide variety of habitats. Most occur in hot desert and cold or hot semi-desert climates, and they are found on every continent but Antarctica. Their common primary characteristic is compound flower heads, technically known as capitula, consisting of sometimes hundreds of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australia
Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller islands. It has a total area of , making it the list of countries and dependencies by area, sixth-largest country in the world and the largest in Oceania. Australia is the world's flattest and driest inhabited continent. It is a megadiverse countries, megadiverse country, and its size gives it a wide variety of landscapes and Climate of Australia, climates including deserts of Australia, deserts in the Outback, interior and forests of Australia, tropical rainforests along the Eastern states of Australia, coast. The ancestors of Aboriginal Australians began arriving from south-east Asia 50,000 to 65,000 years ago, during the Last Glacial Period, last glacial period. By the time of British settlement, Aboriginal Australians spoke 250 distinct l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salad
A salad is a dish consisting of mixed ingredients, frequently vegetables. They are typically served chilled or at room temperature, though some can be served warm. Condiments called '' salad dressings'', which exist in a variety of flavors, are usually used to make a salad. Garden salads have a base of raw leafy greens (sometimes young "baby" greens) such as lettuce, arugula (rocket), kale or spinach; they are common enough that the word ''salad'' alone often refers specifically to garden salads. Other types of salad include bean salad, tuna salad, bread salads (such as fattoush, panzanella), vegetable salads without leafy greens (such as Greek salad, potato salad, coleslaw), rice-, pasta- and noodle-based salads, fruit salads and dessert salads. Salads may be served at any point during a meal: * Appetizer salads – light, smaller-portion salads served as the first course of the meal * Side salads – to accompany the main course as a side dish; examples inclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulmonary Emphysema
Emphysema is any air-filled enlargement in the body's tissues. Most commonly emphysema refers to the permanent enlargement of air spaces ( alveoli) in the lungs, and is also known as pulmonary emphysema. Emphysema is a lower respiratory tract disease, characterised by enlarged air-filled spaces in the lungs, that can vary in size and may be very large. The spaces are caused by the breakdown of the walls of the alveoli, which replace the spongy lung tissue. This reduces the total alveolar surface available for gas exchange leading to a reduction in oxygen supply for the blood. Emphysema usually affects the middle aged or older population because it takes time to develop with the effects of tobacco smoking and other risk factors. Alpha-1 antitrypsin deficiency is a genetic risk factor that may lead to the condition presenting earlier. When associated with significant airflow limitation, emphysema is a major subtype of chronic obstructive pulmonary disease (COPD), a progressiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene-for-gene Relationship
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''. Clayton Oscar Person was the first scientist to study plant pathosystem ratios rather than genetics ratios in host-paras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bremia Lactucae
''Bremia lactucae'' is a plant pathogen. This microorganism causes a disease of lettuce (''Lactuca sativa'') 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 (''formae speciales''). 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. The severity of damage caused by ''Bremia'' can vary depending on environmental conditions. High humidity and cool temperatures are optimal for infection and spread of the disease. Lettuce that is infected with downy mildew causes the plant to become more susceptible for other pathogens. The infected leaf tissue can serve as an entry for secondary infection, particularly to pathogens that cause sof ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Africa
Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surface area.Sayre, April Pulley (1999), ''Africa'', Twenty-First Century Books. . With nearly billion people as of , it accounts for about of the world's human population. Demographics of Africa, Africa's population is the youngest among all the continents; the median age in 2012 was 19.7, when the worldwide median age was 30.4. Based on 2024 projections, Africa's population will exceed 3.8 billion people by 2100. Africa is the least wealthy inhabited continent per capita and second-least wealthy by total wealth, ahead of Oceania. Scholars have attributed this to different factors including Geography of Africa, geography, Climate of Africa, climate, corruption, Scramble for Africa, colonialism, the Cold War, and neocolonialism. Despite this lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asia
Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilisations. Its 4.7 billion people constitute roughly 60% of the world's population. Asia shares the landmass of Eurasia with Europe, and of Afro-Eurasia with both Europe and Africa. In general terms, it is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean, and on the north by the Arctic Ocean. The border of Asia with Europe is a social constructionism, historical and cultural construct, as there is no clear physical and geographical separation between them. A commonly accepted division places Asia to the east of the Suez Canal separating it from Africa; and to the east of the Turkish straits, the Ural Mountains an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europe
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east. Europe shares the landmass of Eurasia with Asia, and of Afro-Eurasia with both Africa and Asia. Europe is commonly considered to be Boundaries between the continents#Asia and Europe, separated from Asia by the Drainage divide, watershed of the Ural Mountains, the Ural (river), Ural River, the Caspian Sea, the Greater Caucasus, the Black Sea, and the waterway of the Bosporus, Bosporus Strait. "Europe" (pp. 68–69); "Asia" (pp. 90–91): "A commonly accepted division between Asia and Europe ... is formed by the Ural Mountains, Ural River, Caspian Sea, Caucasus Mountains, and the Black Sea with its outlets, the Bosporus and Dardanelles." Europe covers approx. , or 2% of Earth#Surface, Earth's surface (6.8% of Earth's land area), making it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactuca Serriola Clump
''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. Its best-known representative is the garden lettuce (''Lactuca sativa''), with its many varieties. "Wild lettuce" commonly refers to the wild-growing relatives of common garden lettuce. Many species are common weeds. ''Lactuca'' species are diverse and take a wide variety of forms. They are annuals, biennials, perennials, or shrubs. Their flower heads have yellow, blue, or white ray florets. Some species are bitter-tasting. Most wild lettuces are xerophytes, adapted to dry habitat types. Some occur in more moist areas, such as the mountains of central Africa. Diversity There are different concepts of the species within ''Lactuca''. It is not clear how many distinct species are known, and estimates vary from 50 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycelis Muralis
''Lactuca muralis'', the wall lettuce, is a perennial flowering plant in the tribe Cichorieae within the family Asteraceae. It is also referred to as ''Mycelis muralis''.Parnell, J. and Curtis, T. 2012. ''Webb's An Irish Flora''. Cork University Press. Its chief characteristic is its open airy clumps of yellow flowers. Each "flower" is actually a composite flower, consisting of 4–5 petal-like flowers (strap or ray flowers), each approximately in length. There are no disc flowers. ''Lactuca muralis'' grows about tall with the lower leaves pinnately toothed and clasping. Description ''Lactuca muralis'' is slender, hairless herb growing from tall. It often has purplish stems, and exudes a milky juice. The lower leaves are lyre shaped, pinnate shaped. The lobes are triangular in shape, the terminal lobe being the largest.Clapham, A.R., Tutin, T.G. and Warburg, E.F. 1968 ''Excursion Flora of the British Isles Second Edition''. Cambridge The upper leaves are stalkless, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
