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Louisa May Alcott August Nemo Biography & Facts

Thistle is the common name of a group of flowering plants characterised by leaves with sharp prickles on the margins, mostly in the family Asteraceae. Prickles can also occur all over the plant – on the stem and on the flat parts of the leaves. These prickles are an adaptation that protects the plant from being eaten by herbivores. Typically, an involucre with a clasping shape similar to a cup or urn subtends each of a thistle's flower heads. The typically feathery pappus of a ripe thistle flower is known as thistle-down. The comparative amount of spininess varies dramatically by species. For example, Cirsium heterophyllum has minimal spininess while Cirsium spinosissimum is the opposite. Typically, species adapted to dry environments have greater spininess. The term thistle is sometimes taken to mean precisely those plants in the tribe Cardueae (synonym: Cynareae), especially the genera Carduus, Cirsium, and Onopordum. However, plants outside this tribe are sometimes called thistles. Biennial thistles are particularly noteworthy for their high wildlife value, producing such things as copious floral resources for pollinators, nourishing seeds for birds like the goldfinch, foliage for butterfly larvae, and down for the lining of birds' nests. A thistle is the floral emblem of Scotland and Lorraine, as well as the emblem of the Encyclopædia Britannica. Taxonomy Genera in the Asteraceae with the word thistle often used in their common names include: Carduus – musk thistle and others Carduinae – burdock root Carlina – carline thistle Carthamus – distaff thistle Centaurea – star thistle Cicerbita – sow thistle Cirsium – common thistle, field thistle and others Cnicus – blessed thistle Cynara – artichoke, cardoon Echinops – globe thistle Notobasis – Syrian thistle Onopordum – cotton thistle, also known as Scots or Scotch thistle Scolymus – golden thistle or oyster thistle Silybum – milk thistle Sonchus – sow thistle Plants in families other than Asteraceae which are sometimes called thistle include: Kali – Russian thistle, Tartar thistle, or tumbleweed, plants formerly classified in the genus Salsola (family Chenopodiaceae) Argemone mexicana – flowering thistle, purple prickly poppy (family Papaveraceae) Eryngium – certain species include the word thistle, such as beethistle, E. articulatum (family Apiaceae) Dipsacus fullonum – German names include Hausdistel, Kartendisteln, Roddistel, Sprotdistel and Weberdistel (family Caprifoliaceae) Ecology Thistle flowers are the favourite nectar sources of the pearl-bordered fritillary, small pearl-bordered fritillary, high brown fritillary, and dark green fritillary butterflies. Thistles and thistle-seed feeders provide important sustenance for goldfinches and are strongly favored by many butterflies besides fritillaries such as the monarch, skippers, and the various types of tiger swallowtail. Hummingbirds will feed on the flowers of the biennial species, which feature large flowers, as compared with the perennial Canada thistle. Some thistles, for example Cirsium vulgare, native to Eurasia, have been widely introduced outside their native range. Control measures include Trichosirocalus weevils. A problem with this approach, at least in North America, is that the introduced weevils may affect native thistles at least as much as the desired targets. Another approach towards controlling thistle growth is using thistle tortoise beetles as a biological control agent; through feeding on thistle plants, thistle tortoise beetles skeletonize the leaves and damage the plant. Thistles have been said to be very important nectar sources for pollinators. Some ecological organizations, such as the Xerces Society, have attempted to raise awareness of their benefits, to counteract the general agricultural and home garden labeling of thistles as unwanted weeds. The monarch butterfly, Danaus plexippus for instance, was highlighted as traditionally relying upon taller large-flowered thistle species such as Tall thistle, Cirsium altissimum, for its migration. Although such organizations focus on the benefits of native thistles, certain non-native thistles, such as Cirsium vulgare in North America, may provide similar benefits to wildlife. Some prairie and wildflower seed production companies supply bulk seed for native North American thistle species, for wildlife habitat restoration, although availability tends to be low. Thistles are particularly valued by bumblebees for their high nectar production. Cirsium vulgare ranked in the top 10 for nectar production in a UK plants survey conducted by the AgriLand project which is supported by the UK Insect Pollinators Initiative. Bull thistle was a top producer of nectar sugar in another study in Britain, ranked third with a production per floral unit of (2323 ± 418μg). Uses Maud Grieve recorded that Pliny and medieval writers had thought it could return hair to bald heads and that in the early modern period it had been believed to be a remedy for headaches, plague, cancer sores, vertigo, and jaundice. Cuisine In Portugal's Beira region, thistle flowers are used in cheese making, as a source of enzymes to coagulate the milk. "Serra da Estrela" is not only the name of a mountain chain in this country, "Serra da Estrela" is also the name of one of the most appreciated cheeses made from sheep's milk. Economic significance Thistles, even if one restricts the term to members of the Asteraceae, are too varied a group for generalisation. Many are troublesome weeds, including some invasive species of Cirsium, Carduus, Silybum and Onopordum. Typical adverse effects are competition with crops and interference with grazing in pastures, where dense growths of spiny vegetation suppress forage plants and repel grazing animals from eating either the thistle plants or neighbouring forage. Some species, although not intensely poisonous, affect the health of animals that swallow more than small amounts of the material. The genus Cynara includes commercially important species of artichoke and some species regarded as major weeds are commercial sources of vegetable rennet used in commercial cheese making. Similarly, some species of Silybum that occur as weeds are cultivated for seeds that yield vegetable oil and pharmaceutical compounds such as Silibinin. Other thistles that nominally are weeds are important honey plants, both as bee fodder in general, and as sources of luxury monofloral honey products. Medicine Milk Thistle, also known as silymarin, has been used to improve liver or gallbladder issues. While not confirmed by the U.S. Department of Health and Human services, milk thistle has shown beneficial results in previous studies for people with HCV. As well as a few studies showing possible results of the thistle as a medicine for individuals with diabetes. It is possible that milk thistle can lower blood sugar levels for individuals with type two diabetes. As a dietary supplement, milk thistle is reco.... Discover the Louisa May Alcott August Nemo popular books. Find the top 100 most popular Louisa May Alcott August Nemo books.