|Cirsium vulgare (spear thistle)|
Cirsium is a genus of perennial and biennial flowering plants in the Asteraceae, one of several genera known commonly as thistles. They are more precisely known as plume thistles. These differ from other thistle genera ( Carduus , Silybum and Onopordum ) in having feathered hairs to their achenes. The other genera have a pappus of simple unbranched hairs.
A perennial plant or simply perennial is a plant that lives more than two years. Some sources cite perennial plants being plants that live more than three years. The term is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also widely used to distinguish plants with little or no woody growth from trees and shrubs, which are also technically perennials.
A biennial plant is a flowering plant that takes two years to complete its biological lifecycle. In the first year, the plant grows leaves, stems, and roots, then it enters a period of dormancy over the colder months. Usually the stem remains very short and the leaves are low to the ground, forming a rosette. Many biennials require a cold treatment, or vernalization, before they will flower. During the next spring or summer, the stem of the biennial plant elongates greatly, or "bolts". The plant then flowers, producing fruits and seeds before it finally dies. There are far fewer biennials than either perennial plants or annual plants.
Asteraceae or Compositae is a very large and widespread family of flowering plants (Angiospermae).
They are mostly native to Eurasia and northern Africa, with about 60species from North America (although several species have been introduced outside their native ranges).
Eurasia is the largest continental landmass on Earth, comprising all of Europe and Asia. The term is a portmanteau of its constituent continents. Located primarily in the Northern and Eastern Hemispheres, it is bordered by the Atlantic Ocean to the west, the Pacific Ocean to the east, the Arctic Ocean to the north, and by Africa, the Mediterranean Sea, and the Indian Ocean to the south. The division between Europe and Asia as two different continents is a historical social construct, with no clear physical separation between them; thus, in some parts of the world, Eurasia is recognized as the largest of the six, five, or even four continents on Earth. In geology, Eurasia is often considered as a single rigid megablock. However, the rigidity of Eurasia is debated based on paleomagnetic data.
Africa is the world's second largest and second most-populous continent, being behind Asia in both categories. At about 30.3 million km2 including adjacent islands, it covers 6% of Earth's total surface area and 20% of its land area. With 1.2 billion people as of 2016, it accounts for about 16% of the world's human population. The continent is surrounded by the Mediterranean Sea to the north, the Isthmus of Suez and the Red Sea to the northeast, the Indian Ocean to the southeast and the Atlantic Ocean to the west. The continent includes Madagascar and various archipelagos. It contains 54 fully recognised sovereign states (countries), nine territories and two de facto independent states with limited or no recognition. The majority of the continent and its countries are in the Northern Hemisphere, with a substantial portion and number of countries in the Southern Hemisphere.
Thistles are known for their effusive flower heads, usually purple, rose or pink, also yellow or white. The radially symmetrical disc flowers are at the end of the branches and are visited by many kinds of insects, featuring a generalised pollination syndrome.They have erect stems and prickly leaves, with a characteristic enlarged base of the flower which is commonly spiny. The leaves are alternate, and some species can be slightly hairy. Extensions from the leaf base down the stem, called wings, can be lacking (Cirsium arvense), conspicuous (Cirsium vulgare), or inconspicuous. They can spread by seed, and also by rhizomes below the surface (Cirsium arvense). The seed has tufts of tiny hair, or pappus, which can carry them far by wind.
Pollination syndromes are suites of flower traits that have evolved in response to natural selection imposed by different pollen vectors, which can be abiotic or biotic, such as birds, bees, flies, and so forth. These traits include flower shape, size, colour, odour, reward type and amount, nectar composition, timing of flowering, etc. For example, tubular red flowers with copious nectar often attract birds; foul smelling flowers attract carrion flies or beetles, etc.
A seed is an embryonic plant enclosed in a protective outer covering. The formation of the seed is part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosperm plants.
In botany and dendrology, a rhizome is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow horizontally. The rhizome also retains the ability to allow new shoots to grow upwards.
Cirsium thistles are used as food plants by the larvae of some Lepidoptera species - see list of Lepidoptera that feed on Cirsium. The seeds are attractive to small finches such as American goldfinch.
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
Lepidoptera is an order of insects that includes butterflies and moths. About 180,000 species of the Lepidoptera are described, in 126 families and 46 superfamilies, 10 per cent of the total described species of living organisms. It is one of the most widespread and widely recognizable insect orders in the world. The Lepidoptera show many variations of the basic body structure that have evolved to gain advantages in lifestyle and distribution. Recent estimates suggest the order may have more species than earlier thought, and is among the four most speciose orders, along with the Hymenoptera, Diptera, and Coleoptera.
The American goldfinch is a small North American bird in the finch family. It is migratory, ranging from mid-Alberta to North Carolina during the breeding season, and from just south of the Canada–United States border to Mexico during the winter.
Most species are considered weeds, typically by agricultural interests. Cirsium vulgare (bull thistle, common thistle, or spear thistle) is listed as a noxious weed in nine US states.Some species in particular are cultivated in gardens and wildflower plantings for their aesthetic value and/or to support pollinators such as butterflies. Some species dubbed weeds by various interest groups can also provide these benefits. Cirsium vulgare , for instance, 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 also a top producer of nectar sugar in another study in Britain, ranked third with a production per floral unit of (2323 ± 418μg). Not only does it provide abundant nectar, it provides seeds and floss for birds, such as the American goldfinch, Spinus tristis , and supports the larvae of a Painted Lady butterfly, Vanessa cardui . A great many native North American plants have weed in their common names, despite their beneficial qualities, such as Asclepias tuberosa , commonly known as butterflyweed. Some other common species are: Cirsium lanceolatum, Cirsium palustre, Cirsium oleraceum .
A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place". Examples commonly are plants unwanted in human-controlled settings, such as farm fields, gardens, lawns, and parks. Taxonomically, the term "weed" has no botanical significance, because a plant that is a weed in one context is not a weed when growing in a situation where it is in fact wanted, and where one species of plant is a valuable crop plant, another species in the same genus might be a serious weed, such as a wild bramble growing among cultivated loganberries. In the same way, volunteer crops (plants) are regarded as weeds in a subsequent crop. Many plants that people widely regard as weeds also are intentionally grown in gardens and other cultivated settings, in which case they are sometimes called beneficial weeds. The term weed also is applied to any plant that grows or reproduces aggressively, or is invasive outside its native habitat. More broadly "weed" occasionally is applied pejoratively to species outside the plant kingdom, species that can survive in diverse environments and reproduce quickly; in this sense it has even been applied to humans.
Cirsium vulgare, the spear thistle, bull thistle, or common thistle, is a species of the Asteraceae genus Cirsium, native throughout most of Europe, Western Asia, and northwestern Africa. It is also naturalised in North America, Africa, and Australia and is an invasive weed in some areas. It is the national flower of Scotland.
Vanessa cardui is a well-known colourful butterfly, known as the painted lady, or formerly in North America as the cosmopolitan.
Some ecological organizations, such as the Xerces Society, have attempted to raise awareness of the benefits of thistles, to counteract the general agricultural and home garden labeling of thistles as unwanted weeds. The monarch butterfly, Danaus plexippus for instance, was highlighted as relying upon thistles such as Tall thistle, Cirsium altissimum , for its migration, as a very important nectar source.Although such organizations focus on the benefits of native thistles, 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.
The Xerces Society is a non-profit environmental organization that focuses on the conservation of invertebrates considered to be essential to biological diversity and ecosystem health. The name is in honor of the extinct California butterfly, the Xerces blue.
Cirsium altissimum is a North American species of plants in the thistle tribe within the sunflower family. Common name is tall thistle or roadside thistle. The species is native to the eastern and Central United States, with a range extending from Massachusetts west to North Dakota and south to Texas and the Florida Panhandle.
Certain species of Cirsium, like Cirsium monspessulanum , Cirsium pyrenaicum and Cirsium vulgare , have been traditionally used as food in rural areas of southern Europe. Cirsium oleraceum is cultivated as a food source in Japan and India.
The word 'Cirsium' derives from the Greek word kirsos meaning 'swollen vein'. Thistles were used as a remedy against swollen veins. The flower blooms April to August.
Onopordum acanthium is a flowering plant in the family Asteraceae. It is native to Europe and Western Asia from the Iberian Peninsula east to Kazakhstan, and north to central Scandinavia, and widely naturalised elsewhere. It is a vigorous biennial plant with coarse, spiny leaves and conspicuous spiny-winged stems.
Zerene eurydice, the California dogface butterfly, is sometimes placed in the related genus as Colias eurydice. This species is endemic to California, and is California's state insect symbol.
Leucanthemum vulgare, commonly known as the ox-eye daisy, oxeye daisy, dog daisy and other common names, is a widespread flowering plant native to Europe and the temperate regions of Asia, and an introduced plant to North America, Australia and New Zealand.
Cirsium palustre, the marsh thistle or European swamp thistle, is a herbaceous biennial flowering plant in the daisy family, Asteraceae.
Cirsium oleraceum, the cabbage thistle or Siberian thistle, is a species of thistle in the genus Cirsium within the sunflower family, native to central and eastern Europe and Asia, where it grows in wet lowland soils.
Glebionis segetum is a species of the genus Glebionis, probably native only to the eastern Mediterranean region but now naturalized in western and northern Europe as well as China and parts of North America. Common names include corn marigold and corn daisy.
Cirsium arvense is a perennial species of flowering plant in the family Asteraceae, native throughout Europe and northern Asia, and widely introduced elsewhere. The standard English name in its native area is creeping thistle. It is also commonly known as Canada thistle and field thistle.
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 flowerheads.
A noxious weed, harmful weed or injurious weed is a weed that has been designated by an agricultural or other governing authority as a plant that is injurious to agricultural or horticultural crops, natural habitats or ecosystems, or humans or livestock. Most noxious weeds have been introduced into an ecosystem by ignorance, mismanagement, or accident. Some noxious weeds are native. Typically they are plants that grow aggressively, multiply quickly without natural controls, and display adverse effects through contact or ingestion. Noxious weeds are a large problem in many parts of the world, greatly affecting areas of agriculture, forest management, nature reserves, parks and other open space.
Cirsium occidentale, with the common name cobweb thistleor cobwebby thistle, is a North American species of thistle in the sunflower family.
Cirsium discolor, the field thistle, is a North American species of plants in the thistle tribe, within the sunflower family. It is native to thirty-three states in the United States as well four Canadian provinces. It occurs across much of eastern and central Canada as well as eastern and central United States. It has been found from New Brunswick west to Saskatchewan and south as far as Texas and Georgia.
The Blue Oak Ranch Reserve, a unit of the University of California Natural Reserve System, is a ecological reserve and biological field station in Santa Clara County, California. It is located on 3,260 acres (13.2 km2) in the Diablo Range, northwest of Mount Hamilton, at 1,500 ft (460 m) elevation.
Cirsium undulatum is a species of thistle known by the common names wavyleaf thistle and gray thistle. It is native to much of central and western North America from British Columbia east to Manitoba and south as far as the State of Durango in Mexico. It has also been found outside of its native range as an introduced species.
Cirsium heterophyllum, also known as melancholy thistle, is an erect spineless herb in the sunflower family. It is native to Europe and western Asia, where it grows in upland meadows, grasslands, road verges and open woodland.
Sisyrinchium sarmentosum is a species of flowering plant in the iris family known by the common names mountain blue-eyed grass and pale blue-eyed-grass. It is native to the Pacific Northwest of North America, where it is known from a part of the Cascade Mountains in Washington and Oregon.
Leontodon hispidus is a species of hawkbit known by the common names bristly hawkbit and rough hawkbit. It is native to Europe but it can be found throughout North America as an introduced species.
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