There are 5 non-native invasive noxious thistles - Bull thistle Cirsium vulgare, Musk thistle Carduus nutans, Scotch thistle Onopordum acanthium and Onopordum tauricum, Plumeless thistle Carduus acanthoides, Canada thistle Cirsium arvense or Breea arvensis. (athomecolorado.com)
Any of several perennial composite plants , especially of genera Cirsium , Carduus , Cynara , or Onopordum , having prickly leaves and showy flower heads with prickly bracts . (wiktionary.org)
Centaurea2
Other plants that may be confused with thistles are Prickly lettuce Lactuca serriola, Prickly poppy Argemone polyanthemos which has a white poppy flower, Prickly sow thistle, Sonchus asper, Yellow starthistle Centaurea solstitialis. (athomecolorado.com)
Just did some armchair botanizing to look as a few more of the fantastic sea urchin dwarf thistles, even Centaurea comes to mind. (nargs.org)
Field thistle2
Cirsium discolor (Field Thistle) , together with Cirsium muticum (Swamp Thistle), is Floyd County's native thistle, and a staple of any butterfly garden. (floydnativeplants.org)
Field Thistle in autumn taken near Scotland, Arkansas, U.S. Photo by Jimmie R Johnson , CC BY-SA 3.0 , via Wikimedia Commons. (floydnativeplants.org)
Spear12
Information on habit, biology, persistence & spread for Spear thistle. (gardenorganic.org.uk)
Spear thistle is a robust biennial or short-lived monocarpic perennial that can be a serious problem in grassland and waste and cultivated ground throughout the UK. (gardenorganic.org.uk)
Spear thistle flowers in June and July but rosettes can survive for up to 4 years without flowering. (gardenorganic.org.uk)
Spear thistle seedlings may emerge in spring and autumn but the main period of emergence is March to April. (gardenorganic.org.uk)
Spear thistle does appear to accumulate a persistent seedbank and seedlings may only emerge after fresh seed has been shed. (gardenorganic.org.uk)
Disturbance of the soil and vegetation has been shown to advance the germination of spear thistle. (gardenorganic.org.uk)
Spear thistle rosettes grow better in grazed than ungrazed pasture because of reduced competition from neighbouring plants. (gardenorganic.org.uk)
Spear thistle reproduces only by seed and it is important to prevent fresh seeding. (gardenorganic.org.uk)
In arable crops, spear thistle seedlings are destroyed by surface cultivations in spring, and by hoeing or spudding as necessary. (gardenorganic.org.uk)
Spear thistle can be pulled out when in flower, or the taproot may be cut below ground when plants are at the rosette stage using a thistle hoe. (gardenorganic.org.uk)
Biennial non-native thistles are easily managed by keeping them from going to seed. (athomecolorado.com)
Asteraceae3
Thistles are in the Asteraceae, sunflower (daisy) family. (athomecolorado.com)
With the exception of the prickly poppy, all of these are in the same Asteraceae, sunflower family as the thistles and are non-natives. (athomecolorado.com)
Thistles are in the Asteraceae (daisy) family and can be biennials or short-lived perennials, natives or non-natives. (ncsu.edu)
Noxious2
Canada thistle is a designated noxious weed under the Nebraska Department of Agriculture's Noxious Weed Program. (naaiatelier-elena.nl)
It … Here is the Canada Thistle, Cirsium arvense, a herbaceous plant that is very thorny and is considered a Noxious Weed. (naaiatelier-elena.nl)
Creeping thistle is a herbaceous perennial plant growing up to 150 cm, forming extensive clonal colonies from thickened roots that send up numerous erect shoots during the growing season. (naaiatelier-elena.nl)
The standard English name in its native area is creeping thistle. (naaiatelier-elena.nl)
Unlike creeping thistle ( C. arvense ), the feathery pappus remains attached firmly to the seed as an aid to wind dispersal. (gardenorganic.org.uk)
These biological control measures will not completely manage / control Canada thistle alone, but are an IMP tool and help suppress growth. (naaiatelier-elena.nl)
North America1
Sadly, Cirsium discolor has been targeted for eradication largely due to the invasive behavior of its non-native cousins, the European Bull Thistle ( Cirsium vulgare ) and Canada Thistle ( Cirsium arvense ) which, despite the name, is not native to North America. (floydnativeplants.org)
Scotch1
Scotch thistle ( Onopordum acanthium et al. (wiktionary.org)
Larvae2
Thistle stem gall fly larvae (Urophora cardui) attack the primary lateral stems. (naaiatelier-elena.nl)
Tortoise beetle Cassida rubiginosa larvae and feeding damage on Cirsium arvense . (iobc.info)
20201
If you would like to learn more about Colorado's thistles, Larimer County Weed District has a booklet on Colorado's thistles both native and non-native, visit larimer.org/sites/default/files/uploads/2020/2019_thistle_guide_5.5_x_8_-_dec_30_1.pdf . (athomecolorado.com)
Download the Invasive Species Council of BC's Factsheet for Canada Thistle here. (naaiatelier-elena.nl)
Nebraska Extension Publications has a number of publications on thistle management and other invasive species. (naaiatelier-elena.nl)
Invasive Species, 2270 Old Penitentiary Road, Boise, ID, 83712, United States It is a non-native invasive species from Europe, and landowners with Canada thistle on their property are obligated to take measures to control it. (naaiatelier-elena.nl)
Cirsium discolor can be grown in most any sunny mesic cultivated garden, though it is a widely adapted pioneer species able to scrape out a living in many disturbed or subxeric habitats. (floydnativeplants.org)
Cirsium discolor is noted of Special Value to Native Bees by the Xerces Society ( Wildflower.org ), as a keystone species for 15 species of native bees by Dr. Doug Tallamy, and as a provider of nesting habitat for some native bees including leaf miner bees which nest in the hollow stems ( Xerces , 2017). (floydnativeplants.org)
Two species, Cirsium arvense and C. vulgare are non-native and considered weedy. (ncsu.edu)
There are so many species from such a lot of genera that I thought I'd start a board that was more general - Panayoti and others have been rapping on spiny plants on the Cactus discussions and I love pricklies (although Monica doesn't so I have to keep them out of touch with one another) but above all I think thistles of all sorts are the great gems. (nargs.org)
Daisy1
The Oxford Dictionary defines a thistle as "A widely distributed herbaceous plant of the daisy family, which typically has a prickly stem and leaves and rounded heads of purple flowers. (athomecolorado.com)
Worst invasive1
One of the worst invasive pests here is Cirsium vulgare or Bull Thistle. (nargs.org)
Pasture1
Unlike the many native thistles found in Oregon, Canada thistle can quickly overrun an area and displace native plants, reduce agricultural yield, and create problems for … Once Canada thistle has invaded, it is very important to maintain soil fertility and moisture at optimum levels to favor crop or pasture plant establishment and growth. (naaiatelier-elena.nl)
Nectar3
Native thistles attract many butterflies (including the monarch butterfly) with their copious nectar. (floydnativeplants.org)
Thistles are a high-value nectar plant for bees and butterflies, and songbirds eat the seeds and use the tufts of the seeds for their nests. (ncsu.edu)
A fritillary patrolling the meadow stops to sip nectar from a thistle. (sharpeatmanguides.com)
Canada13
There's a good reason Canada thistle has a reputation as a highly invasive, aggressive spreader. (naaiatelier-elena.nl)
The introduced Canada thistle, Matt pointed out, can choke out all sorts of native vegetation as well as native thistles. (naaiatelier-elena.nl)
Canada thistle is a rhizomatous, perennial, herbaceous plant. (naaiatelier-elena.nl)
Currently several weevils and a gall fly have been released to target Canada thistle. (naaiatelier-elena.nl)
All of these thistles are biennials (two growing season growth cycle) with the exception of Canada thistle which is a perennial. (athomecolorado.com)
Canada thistle is harder to manage as it lives multiple years and spreads by both seed and roots. (athomecolorado.com)
The majority of the Canada thistle plant mass is in the roots so managing with the root system is the key to eradicating it. (athomecolorado.com)
Trying to dig out the Canada thistle root system is next to impossible. (athomecolorado.com)
Some property owners try to manage Canada thistle by pulling or mowing it to keep it from having leaves so it can photosynthesize and store energy in the roots. (athomecolorado.com)
Synthetic herbicides do translocate and kill the root system and may be the best method to manage large Canada thistle infestations. (athomecolorado.com)
Canada thistle can spread quickly, so early detection and removal is important. (farmfoodfamily.com)
To remove Canada thistle, first cut the plant down to ground level. (farmfoodfamily.com)
Canada thistle is a tough weed, but with persistence you can get rid of it! (farmfoodfamily.com)
PLANTS3
There are 20 thistles native to Colorado and they are desirable plants. (athomecolorado.com)
Assuming that you don't want to have to work through a dichotomous key (how botanists identify plants), there are some simple features that may indicate whether a thistle is either native or non-native. (athomecolorado.com)
Native thistles are a great option in a meadow garden or naturalized area when looking for native host plants for the Little Metalmark butterfly or the Painted Lady butterfly. (ncsu.edu)
As a result, if you decide you don't want to continue growing Cirsium discolor , cut the flowers before they go to seed or remove the seedheads before they are dispersed. (floydnativeplants.org)
Cirsium discolor can be distinguished from non-native thistles by the white woolly undersides of the leaves which none of the non-native thistles have and all North America's native thistles do have. (floydnativeplants.org)
Each thistle plant can produce 1,000 up to 1,500 seeds per shoot. (naaiatelier-elena.nl)
Fewer than 10 seedlings are likely to develop from the seeds shed by an individual thistle plant. (gardenorganic.org.uk)
Tend2
Invasive thistles tend to grow taller (4 to 12') and in large, dense stands. (athomecolorado.com)
Thistles tend to thrive in anthropogenic (human-made) disturbance, which might in part explain its presence in the agrarian imagination, faded though that presence has become in the modern era. (floydnativeplants.org)