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Centaurea ×moncktonii
Meadow knapweed is a fertile hybrid between black knapweed (''Centaurea nigra'') and brown knapweed (''Centaurea jacea''). It is also known by the common names of hybrid knapweed or protean knapweed. The taxonomic status of the species is uncertain, and meadow knapweed has been variously described as different species. The ''Flora of North America'' refers to meadow knapweed as the nothospecies ''Centaurea × moncktonii''. Description Meadow knapweed is a perennial forb that grows to 20–40 inches tall. The branched stems rise above a woody root crown. The seedlings have a tap root, but the mature plants develop a cluster of roots below the root crown. Meadow knapweed reproduces mostly by seed, but its root fragments can resprout after disturbance. The seeds naturally disperse only a few meters, but they can disperse further via animals, humans, vehicles, or water. The leaves become progressively smaller up the stem. The lower leaves can have either smooth, coarsely lobed, or t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centaurea Nigra
''Centaurea nigra'' is a species of flowering plant in the family Asteraceae known by the common names lesser knapweed, common knapweed and black knapweed. A local vernacular name is hardheads. It is native to Europe but it is known on other continents as an introduced species and often a noxious weed. Although the plant is often unwanted by landowners because it is considered a weed by many, it provides a great deal of nectar for pollinators. It was rated in the top five for most nectar production (nectar per unit cover per year) in a UK plants survey. It also placed second as a producer of nectar sugar per floral unit, among the meadow perennials, in another study in Britain. Description It is a herbaceous perennial growing up to about a metre in height. The leaves are up to long, usually deeply lobed, and hairy. The lower leaves are stalked, whilst the upper ones are stalkless. The inflorescence contains a few flower heads, each a hemisphere of black or brown bristly ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centaurea × Moncktonii NY-dist-map
''Centaurea'' () is a genus of over 700 species of herbaceous thistle-like flowering plants in the family Asteraceae. Members of the genus are found only north of the equator, mostly in the Eastern Hemisphere; the Middle East and surrounding regions are particularly species-rich. In the western United States, yellow starthistles are an invasive species. Around the year 1850, seeds from the plant had arrived to the state of California. It is believed that those seeds came from South America. Common names Common names for this genus are centaury, centory, starthistles, knapweeds, centaureas and the more ambiguous "bluets"; a vernacular name used for these plants in parts of England is "loggerheads" ( common knapweed). The ''Plectocephalus'' group – possibly a distinct genus – is known as basketflowers. "Cornflower" is used for a few species, but that term more often specifically means either '' C. cyanus'' (the annual cornflower) or '' Centaurea montana'' (the perenn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Invasive Plants
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native species that become harmful to their native environment after human alterations to its food webfor example the purple sea urchin (''Strongylocentrotus purpuratus'') which has decimated kelp forests along the northern California coast due to overharvesting of its natural predator, the California sea otter (''Enhydra lutris''). Since the 20th century, invasive species have become a serious economic, social, and environmental threat. Invasion of long-established ecosystems by organisms is a natural phenomenon, but human-facilitated introductions have greatly increased the rate, scale, and geographic range of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Invasive Species Compendium
The Invasive Species Compendium (ISC) is an online, open access reference work covering recognition, biology, distribution, impact, and management of invasive plants and animals produced by CAB International alongside an international consortium. It comprises peer-reviewed datasheets, images, and maps, a bibliographic database, and full text articles. New datasheets, data sets, and scientific literature are added on a weekly basis. The ISC has been resourced by a diverse international consortium of government departments, non-governmental organizations, and private companies. Coverage The Invasive Species Compendium currently covers over 1,500 species with over 7,000 basic summary datasheets and 1,500 detailed datasheets. In addition, it provides access to over 1,100 full text articles (in PDF Portable Document Format (PDF), standardized as ISO 32000, is a file format developed by Adobe in 1992 to present documents, including text formatting and images, in a manner independen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metzneria Paucipunctella
''Metzneria paucipunctella'' is a species of moth known as the spotted knapweed seed head moth. It is used as an agent of biological pest control against noxious knapweeds, particularly spotted knapweed (''Centaurea maculosa''). The adult moth is narrow-bodied and about 8 millimeters long. It is brownish-gray and lightly speckled. It has large recurved antennae. The female lays about 80 eggs, depositing each at the base of a flower head. In about ten days the larva emerges and burrows into the flower head where it feeds on the developing seeds and florets. The larva is a small, plump white grub with a dark head and visible body segments. It overwinters inside the seed head and pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...tes the following spring. This moth is native t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urophora Quadrifasciata
''Urophora quadrifasciata'' is a species of tephritid or fruit flies in the genus ''Urophora'' of the family Tephritidae. The host plant for the larvae is usually a knapweed (''Centaurea'' sp), and because of this, it is used to control ''Centaurea stoebe''. Distribution Europe & Kazakhstan, North Africa & Iran; introduced North America & Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma .... References Urophora Insects described in 1826 Diptera of Europe Diptera of Asia Diptera of Africa {{Urophora-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urophora Affinis
''Urophora affinis'' is a species of tephritid or fruit flies in the genus ''Urophora'' of the family Tephritidae. It has been released in the United States and Canada as a biocontrol agent to control spotted knapweed. ''U. affinis'' became established in Montana in 1973. Life history ''U. affinis'' is multivoltine and overwinters as a larva in knapweed flower heads. In June, adults oviposit on seed heads. Each female can produce about 120 eggs. It has been shown to reduce seed production in knapweed (spotted and diffuse) by up to 95% Harris P. 1980. Effects of Urophora affinis Frfld, and U. quadrifasciata (Meig.) (Diptera: Tephritidae) on ''Centaurea diffusa'' Lam. and ''C. maculosa'' Lam. (Compositae). Zeitschrift fur Angewandte Entomologie 90:190-201. but that is insufficient for effective management of either species.Powell RD. (1990) The functional forms of density-dependent birth and death rates in diffuse knapweed (Centaurea diffusa) explain why it has not been controlled b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Larinus Obtusus
''Larinus obtusus'' is a species of true weevil known as the blunt knapweed flower weevil. It is used as an agent of biological pest control Biological control or biocontrol is a method of controlling pests, such as insects, mites, weeds, and plant diseases, using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also invo ... against noxious knapweeds, especially spotted knapweed (''Centaurea maculosa''). The adult weevil is dark brown with a large, bulbous snout. It is 5 to 7 millimeters (0.19 to 0.27 inches) long in total. It is active throughout the summer when the female lays yellow eggs in the opened flower head. The larva emerges and feeds on the developing seeds inside the head. The larval stage lasts 17 days, after which the larva constructs a cocoon from the remnants of the seeds and pupates within it for about nine days. Most of the damage to the plant is done by the larva's feeding on the seeds; t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plagiobothrys Hirtus
''Plagiobothrys hirtus'', the rough popcornflower, is a plant species with only about a dozen reportedly extant occurrences, all within the Umpqua River watershed in Douglas County, Oregon. It is federally listed endangered in the United States of America. In fact ''P. hirtus'' is now considered to be one of the top three most endangered vascular plant species in the Northwest. The state of Oregon has ranked this plant as its number one recovery priority due to its high degree of threat as well as its high rating in recovery potential. Its recovery depends on conservation of existing populations as well as reintroduction of new populations in protected and species-appropriate areas. The habitats most suitable for ''P. hirtus'' are seasonal wetlands, which are inundated with water from late fall until spring, but may dry out in summer. However, development, agriculture, and fire suppression have all played a role in the alteration and elimination of much of this species’ habitat. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centaurea Jacea
''Centaurea jacea'', brown knapweed or brownray knapweed, is a species of herbaceous perennial plants in the genus ''Centaurea'' native to dry meadows and open woodland throughout Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia .... It grows to tall, and flowers mainly from June to September. In Britain and America, it is often found as a hybrid of black knapweed, '' Centaurea nigra''. Unlike the black knapweed, the flower heads always look as if they are rayed, forming a more open star rather than a brush-like tuft. '' Centaurea ×moncktonii'' is a fertile hybrid between black knapweed and brown knapweed. References External links * jacea Flora of Norway Plants described in 1753 Taxa named by Carl Linnaeus Flora of Maghreb Flora of Andorra {{Cynareae-stu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centaurea Diffusa
''Centaurea diffusa'', also known as diffuse knapweed, white knapweed or tumble knapweed, is a member of the genus ''Centaurea'' in the family Asteraceae. This species is common throughout western North America but is not actually native to the North American continent, but to the eastern Mediterranean. Description Diffuse knapweed is an annual or biennial plant, generally growing to between 10 and 60 cm in height. It has a highly branched stem and a large taproot, as well as a basal rosette of leaves with smaller leaves alternating on the upright stems. Flowers are usually white or pink and grow out of urn-shaped heads carried at the tips of the many branches. Diffuse knapweed often assumes a short rosette form for one year, reaching maximum size, then rapidly growing and flowering during the second year. A single plant can produce approximately 18,000 seeds. Synonyms * ''Centaurea microcalathina'' Tarassov * ''Centaurea cycladum'' Heldr. * ''Centaurea parviflora'' Sib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centaurea Solstitialis
''Centaurea solstitialis'', the yellow star-thistle, is a species of thorny plant in the genus '' Centaurea'', which is part of the family Asteraceae. A winter annual, it is native to the Mediterranean Basin region and invasive in many other places. It is also known as golden starthistle, yellow cockspur and St. Barnaby's thistle (or Barnaby thistle). Description ''Centaurea solstitialis'' is an annual herb from the family Asteraceae. During the vegetative stage it forms a rosette of non-spiny leaves, between in diameter. As the summer approaches, it produces a flowering stem up to in height. The leaves at the base are lobed and range between in length, while the ones on the stem are unlobed and smaller. Between May and October, the stem produces numerous spinous flower heads (capitula) about across, containing between 10–50 yellow flowers, with spines between . Flowers within capitula are pollinated by insects and each capitula produces 10–50 seeds, some with and som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
