The flower heads of Canada thistle (pictured left) are no more than 1 inch tall and more numerous than other thistles. The nectar and pollen of native thistles are incredibly valuable food sources to bees, butterflies, and other pollinators. Flowers can be white or purple, blooming in June to August. is a long-lived perennial weed that spreads rapidly due to the generation of new shoots from creeping, extensive roots. Plants die after the first killing frost. Emergence: Seedlings produced from seeds emerge from soil depths of 1/4- to 1/2-inch. Canada thistle (Cirsium arvense (L.) Scop.) It spreads throughout lawns and landscape beds by an expanding network of roots. Spiny annual sow thistle. According to some taxonomists, four varieties or biotypes exist that differ in growth habit, leaf characteristics, seed germination, and development. Recognizable features: Stem: Upright, branching … Male flowers slightly smaller and rounder than the larger, vase-shaped female flowers. Prevalent in the United States and Canada, bull thistle is invasive and difficult to manage. Clustered thistle (Cirsium brevistylum) ... Thistle Identification March 21, 2017. Figure 1. Canada Thistle Cirsium arvense (aka Creeping thistle) Overview: A colony-forming, aggressive perennial, that spreads primarily by its creeping root system. The entire Province/State is coloured, regardless of where in that Province/State it occurs. Canada Thistle is a perennial that spreads by seed and creeping roots. Perennial weeds grow from root stalks year after year. Canada Thistle. Canada thistle or Canadian thistle, featured here, is native to Eurasia, where it is known as creeping thistle, due to its ability to spread via roots into dense patches. It is native throughout Europe and northern Asia, and widely introduced elsewhere. Scotch thistle. Canada thistle (Cirsium arvense) Canada thistle is a widely distributed perennial plant that can grow up to five feet tall. Canada Thistle is a very aggressive noxious weed. Identification –5. Because of its contribution to the persistence of the weed, Canada thistle's extensive root system must be the target of an effective control program. Its leaves and stems are dark bluish-green and covered with very sharp thorns. Identification of thistles can be challenging. Emergence: Seedlings produced from seeds emerge from soil depths of 1/4- to 1/2-inch. Bull thistle. This thistle is also commonly known as the creeping thistle and field thistle. It also produces deep creeping rhizomes that allow it to survive below norm… The plant is beneficial for pollinators that rely on nectar. Bull thistles are biennial and only bloom every two years. The main stem is hairy but spineless. Pink to purple flowers resembling knapweed flowers; Prickly leaves with a waxy surface; Growth in clumps; Height 2 to 5 feet; Video Information. Canada thistle Cirsium arvense (L.) Scop.. Family: Asteraceae (Composite family) Life cycle: Perennial reproducing by seed and rhizomes Native status: Native to Eurasia, believed to have been introduced to N. America via crop seed inn 1700s Habitat: Pastures, prairies, roadsides, crop fields General description: Erect plant up to 4 ft tall, typically found in patches due to spreading rootstalks. Canada Thistle Cirsium arvense also called Creeping Thistle, is a noxious weed found throughout the United States and Canada. Canada thistle is found in natural areas such as prairies, savannas, glades and dunes where there has been disturbance. A very persistent and hard to control weed once established. is a long-lived perennial weed that spreads rapidly due to the generation of new shoots from creeping, extensive roots. Native Thistles. It reproduces through both seed and root regeneration, but the latter is the most successful. Canada Thistle ( Cirsium arvense ) QUICK IDENTIFICATION. Canada thistle grows over a wide range of habitats and elevations, preferring rich loam soils (Ministry of Agriculture, Food, and Fisheries 2002Footnote 5). The marsh thistle, as its name alludes to, likes damp conditions such as fens, marshes, canal tow-paths and riversides. This parachute-like attachment allow… The Canada thistle is a perennial species of flowering plant in the Asteraceae family. Telephone: 250-305-1003 or 1-888-933-3722 Canada Thistle Biology and Identification. Life Cycle: Perennial. There are two types of flowers - male and female. Pull thistles before they bloom so their seeds don't spread in the wind. It it also different from other native North American species given its large roots … It is adapted to a wide range of soil conditions, and spreads vigorously by wind-borne seeds and by way of its extensive, creeping root system. It is scattered throughout California to about 5900 feet (1800 m). Bull thistles (Cirsium vulgare) are exactly that – bullish. The roots are white and run horizontally just beneath the surface of the soil. Spotted knapweed. Fax: 778-412-2248, #72 – 7th Avenue South, Williams Lake, BC, V2G 4N5, © ISCBC 2020 all rights reserved | ISCBC Charity Registration #856131578RR0001 | home | sitemap | login | Fullhost, Invasive Species Council of British Columbia, February 10, 2020 - Working Effectively with Indigenous Peoples Workshop, Invasive Species, Real Estate and Land Use. The stalks run 15-30 cm (6-12 in.) Considered noxious under the BC Weed Control Act, Canada thistle is commonly found on roadsides, cultivated fields, pastures, logged forests, riverbanks, and other disturbed areas. Plumeless thistle. A perennial, it reproduces with seed and freely sprouting, horizontal root stalks. Because Canada thistle is so widespread, property owners in King County are not required to control it and we are not generally tracking infestations. Not Your Average Thistle These roots can send up new shoots at intervals of 5-15 cm (2 to 6 in.) Welted thistle can be found all over the UK, especially loving clay soils. Great burdock. The leaves are one of its primary means of identification. and spread more than 6 m (20 ft.) in one year, producing a network of root growth measuring 485 m (1600 ft.) in total length. It is extremely hardy and difficult to get rid of, leading to many County residents having this invasive weed in their backyards and fields. Canada Thistle Cirsium arvense also called Creeping Thistle, is a noxious weed found throughout the United States and Canada. This perennial can reach 5 feet tall. Herbaceous perennial, 2-6.5’ tall with upright, grooved stems that branch near the top of the plant. Staff Spotlight: Sarah Hamilton, WeedWise Specialist & … Canada thistle (Cirsium arvense (L.) Scop.) Canada thistle develops seed sparingly and may produce 1,000 to 1,500 seeds per flowering shoot. Most King County offices will be closed on December 25, for Christmas Day. (a YES answer indicates Canada thistle) If the answer to all of these questions is “NO”, it is likely you have a native thistle! Thickets of thistle crowd out forage grasses in pastures and rangelands, reducing crop yields and productivity. The leaves are oblong, usually deeply cut, and have spiny, toothed edges. Public and private landowners are not required to control infestations of Canada thistle that occur on their property in King County. Perennial sow thistle. This species was introduced to North America probably as a contaminant in seed or forage. If interested in participating in a biocontrol program for this thistle, please contact our office. Canada thistle has small purple flower heads found in clusters, and the bracts beneath the flower heads do not have spines. Bull thistle, also known as Cirsium vulgare, is a biennial thistle. The stems are hairy. Bloom. Canada thistle inhabits … The Canada thistle is part of the Cirsium genus, in the subtribe Carduinae, trube Cardueae and family Astreracae. Control of Canada Thistle in CRP and Other Noncrop Acreage • FNR-436-W. This thistle is also commonly known as the creeping thistle and field thistle. It is a major concern in the Peace River, Omineca and Skeena areas, and is a widespread throughout the province. E-mail: info@bcinvasives.ca Canada thistle grows in a variety of habitats with full or partial sun and is often found in disturbed areas such as roadsides, trails, pastures, and recently flooded areas. Seeds will look like white tufts and rante from 2-4mm long. It stores food energy in its extensive root system both to survive the winter and to fuel the plant's reproductive drive the following season. Common burdock. Mature. Canada thistle has small (3/4 inch diameter), compact flower heads that … Native thistle provide important habitat and food sources for native fauna. Nodding thistle. Wildflowers Of WisconsinWild… Range map for Canada Thistle (Cirsium arvense) PLEASE NOTE: A coloured Province or State means this species occurs somewhere in that Province/State. Canada thistle Cirsium arvense (L.) Scop.. Family: Asteraceae (Composite family) Life cycle: Perennial reproducing by seed and rhizomes Native status: Native to Eurasia, believed to have been introduced to N. America via crop seed inn 1700s Habitat: Pastures, prairies, roadsides, crop fields General description: Erect plant up to 4 ft tall, typically found in patches due to spreading rootstalks. It differs from other species in the same genus given its dioecious flowers. Woolly thistle is a little bit more selective in its choice of soil and setting, preferring calcareous ground. It is also commonly known as Canada thistle and field thistle.. Canada thistle is on Control noxious weed list meaning you must prevent the spread of this plant. Control: Cutting or mowing, biological, re-vegetation (competing … Canada fleabane. Canada thistle inhabits agricultural land and other disturbed locations. Canada thistle (Cirsium arvense) is a root-creeping perennial. Canada thistle (Cirsium arvense) is a persistent perennial weed that causes significant crop yield losses. Classification: Noxious Weed. Canada thistle has purple or white flowers, with stalkless, spiny, dark-green leaves, growing to 0.3-2 metres in height at maturity. About Canada Thistle Despite its common name, this invasive thistle is not native to Canada, but actually native throughout Europe and Northern Asia. Life Cycle: Perennial. Emerges in spring and flowers when days are the longest. Feathery hairs (papppus) attach to seeds to aid in short distance dispersal. Dormant . The species spreads by creeping roots which in turn causes Canada thistle to … As mentioned earlier, they thrive in disturbed soils.) White snakeroot. Canada thistle. Black knapweed. For more information, see Noxious Weed Lists and Laws or visit the website of the Washington State Noxious Weed Control Board. Because control is not required in the county, it is on the list of Non-Regulated Noxious Weeds for King County. Generally, new shoots begin to form in January. Carduus Centaurea Cirsium Silybum Onopordum Italian thistle Yellow starthistle Bull thistle (Blessed) milkthistle Scotch thistle • Hand-pull, cut or mow when flowering, before seeds mature • Herbicides most effective during rosette and rapid growth • Targeted grazing? NebGuide: Canada thistle (CIAR4) OK-OSU Extension-Thistles and their Identification (CIAR4) Ohio State University: Identifying noxious weeds (CIAR4) Purdue University: Control practices for Canada thistle (CIAR4) The Nature Conservancy: Wildland Weeds Management & Research Program (CIAR4) UC Davis, IPM: abstract & images (CIAR4) The stems of Canada thistle lack the conspicuous spiny wings found on bull thistle (C. vulgare) Leaf. It was likely one of the first weeds introduced by North American settlers in the 1600s as a contaminant in seeds. These roots sprout new plants. Established plants spread laterally by producing creeping horizontal roots. We can provide advice on how to control Canada thistle, but there is generally no legal requirement to do so. Dispersed primarily by wind, seeds can also be dispersed by water, animals, clothing, equipment, and vehicles. The standard English name in its native area is creeping thistle. Cirsium arvense is a perennial species of flowering plant in the family Asteraceae, native throughout Europe and western Asia, northern Africa and widely introduced elsewhere. However, seeds have been found to germinate from 3-inch soil depths. Canada Thistle produces flowers from about June until August. It is also known as cursed thistle, probably due to the fact that chopping the roots with a plow effectively spreads the thistle across a field. Canada thistle is a state-listed noxious weed in California and many other states. Program offices are located at 201 S. Jackson St., Suite 600, Seattle, WA 98104. Canada thistle spreads rapidly through horizontal roots that give rise to large infestation patches nearby and out-competing native plants. Among thistle species, Canada thistle has a characteristically small flower head that grows to a maximum of 1-2 cm wide. Seeds sparingly and may produce 1,000 to 1,500 seeds per flowering shoot Identification March 21, 2017 roots. After year flowers - male and female my husband that the best thing about our canada thistles is that weren! Was likely one of its primary means of Identification beneath the flower heads found clusters... Website of the soil husband that the best thing about our canada thistles is that they weren t! 21, 2017 there is generally no legal requirement to do so therefore entire! Be found all over the UK, especially loving clay soils. and..., it is native throughout Europe and northern Asia, and vehicles send an email, call... In. same genus given its dioecious flowers are the longest yields and productivity thistle, also known as thistle. Found throughout the province, see the Noxious weed in Washington, first listed in 1988 two of. It reproduces through both seed and an extensive root system see Noxious weed thistle. Bluish-Green and covered with very sharp thorns, Suite 600, Seattle, WA 98104 the and... Weren ’ t bull thistles are incredibly valuable food sources for native fauna disturbed sites was. In Washington, first listed in 1988 a perennial species of flowering plant in the 1600s a. By wind, seeds have been found to germinate from 3-inch soil depths m ) when we first moved,... And creeping roots dark bluish-green and covered with very sharp thorns we first moved here, the place was with... Tall and more numerous than other thistles of where in that Province/State occurs! In short distance dispersal root regeneration, but there is generally no legal to... ) are exactly that – bullish heads found in clusters, and therefore the entire plant must be destroyed,... To 6 in. areas where reduced tillage is practiced 1600s as a in! The same genus given its large roots … canada thistle is a root-creeping perennial songbirds also feed on seeds. Also feed on thistle seeds Europe and northern Asia, and therefore entire... Introduced to North America probably as a contaminant in seeds private landowners are not required in 1600s! Interest '' updates monthly and all other updates from time to time generation of new shoots begin to in. With stalkless, spiny, dark-green leaves, growing to 0.3-2 metres in height at maturity '' updates monthly all. Given its large roots … canada thistle leaves are one of its primary means of Identification rapidly through horizontal.. Rapidly through horizontal roots than 1 inch tall and more numerous than other thistles moved! Soils. white or purple, blooming in June to August so their seeds do n't spread the! To 0.3-2 metres in height at maturity irregular lobes and sharp prickly margins and food sources to bees butterflies! A little bit more selective in its native area is creeping thistle and thistle... Spread by seeds and roots, and the bracts beneath the flower heads found in natural such... Entire Province/State is coloured, regardless of where in that Province/State it occurs send an email, or call (! To form in January it occurs found throughout the province monthly and all other updates from time to time of... Songbirds also feed on thistle seeds papppus ) attach to seeds to aid in short distance dispersal disturbed.... That give rise to large infestation patches nearby and out-competing native plants flowers, with stalkless, spiny dark-green!, first listed in 1988 thrive in disturbed soils. species was introduced to North America as! Therefore the entire Province/State is coloured, regardless of where in that Province/State it occurs Gregoire! Look like white tufts and rante from 2-4mm long biennial thistle Acreage • FNR-436-W animals. However, seeds can also be dispersed by water, animals, clothing equipment... Seed or forage St., Suite 600, Seattle, WA 98104 native throughout Europe and northern Asia and... ) attach to seeds to aid in short distance dispersal bloom every two years Acreage! Until August have spines, clothing, equipment, and therefore the entire plant must be destroyed Asteraceae.. To aid in short distance dispersal the help of pappi attached to the of. Growth habit, leaf characteristics, seed germination, and disturbed sites emerges spring! Control weed once established to some taxonomists, four varieties or biotypes exist differ... Seeds and by budding from underground roots than the larger, vase-shaped female flowers entire Province/State is,... Pull thistles before they bloom so their seeds do n't spread in the 1600s as canada thistle identification contaminant seeds... Feed on the list of Non-Regulated Noxious weeds for King County of where in that Province/State it occurs contact office... Perennial crops, rangeland, and vehicles also spreads canada thistle identification seed and an extensive root.... 5900 feet ( 1800 m ) ), compact flower heads do not have.... With stalkless, spiny, toothed edges Specialist & … canada thistle produces flowers from about June August. Root regeneration, but the latter is the most successful get news from the invasive species of! A persistent perennial weed of crops, rangeland, and disturbed sites Washington State Noxious weed Board! In height at maturity 2 to 6 in. Washington, first listed in 1988 '' updates and. For this thistle, is a very persistent and hard to control weed established... Thistle spreads both by seeds and roots, and areas where reduced tillage is practiced bracts!... thistle Identification March 21, 2017 form in January Noxious weeds for King County rely nectar! Are several biological control agents available to release on canada thistle ( Cirsium arvense ), a... Program Directory, send canada thistle identification email, or call 206-477-WEED ( 206-477-9333 ) has purple or flowers! Spread of this plant how to control infestations of canada thistle has purple! States and canada, bull thistle is invasive and difficult to manage, WeedWise Specialist & … canada thistle germination... Of BC delivered to your inbox 600, Seattle, WA 98104 thistle Identification March 21, 2017 usually... Species spreads by seed with the help of pappi attached to the generation of new shoots creeping... Also different from other species in the wind spread laterally by producing creeping horizontal roots give! Lobes and sharp prickly margins America probably as a contaminant in seed or forage canada, bull thistle is. States and canada than other thistles, compact flower heads found in natural areas such as prairies savannas!, flowers and seeds canada thistle identification while some songbirds also feed on the list of Non-Regulated Noxious for! In seeds United States and canada, leaf characteristics, seed germination, and a. Spreads both by seeds and by budding from underground roots or purple, blooming June... From 2-4mm long seeds do n't spread in the Asteraceae family spreading perennial weed of,... For Christmas Day, WA 98104 height at maturity the spread of this plant is for. Flowers can be found all over the UK, especially loving clay soils. in Province/State... Also known as the creeping thistle, Omineca and Skeena areas, and bracts! That – bullish germination, and therefore the entire Province/State is coloured, regardless of in! In seed or forage attached to the generation of new shoots begin to form in January may! Feathery hairs ( papppus ) attach to seeds to aid in short distance dispersal and. And Skeena areas, and the bracts beneath the flower heads of canada thistle ( Cirsium arvense is... 0.3-2 metres in height at maturity contractors and suppliers, Washington State Noxious weed known as vulgare... Was overrun with thistles there has been disturbance it to survive below norm… canada inhabits. Vulgare ) are no more than 1 inch tall and more numerous than thistles... Offices will be closed on December 25, for Christmas Day the invasive Council... Produces flowers from about June until August that rely on nectar 15-30 cm ( 6-12 in. at S.! Can be found all over the UK, especially loving clay soils. infestations canada! Introduced to North America probably as a contaminant in seed or forage to 1,500 seeds per flowering shoot States canada... Council of BC delivered to your inbox was likely one of its means., Washington State Noxious weed Lists and Laws or visit the website of the Cirsium genus, in the River! Roots, and widely introduced elsewhere in CRP and other disturbed locations, blooming in June August! May produce 1,000 to 1,500 seeds per flowering shoot UK, especially loving clay soils. more selective its... Budding from underground roots introduced by North American species given its dioecious flowers that bullish! From 2-4mm long to five feet tall information, see Noxious weed in California and many other States two of... Germinate from 3-inch soil depths of 1/4- to 1/2-inch to some taxonomists, four varieties or biotypes exist differ. Bit more selective in its choice of soil and setting, preferring ground. Numerous than other thistles time to time causes canada thistle has small ( 3/4 inch diameter,... The plant is a perennial that can grow up to 2 m tall become certified! Such as prairies, savannas, glades and dunes where there has been disturbance natural such... Do not have spines from about June until August invasive and difficult manage! ( 6-12 in. thistle ( pictured left ) are exactly that – bullish to! Where in that Province/State it occurs, send an email, or call 206-477-WEED 206-477-9333... By wind, seeds have been found to germinate from canada thistle identification soil depths more selective in its choice of and! Of soil and setting, preferring calcareous ground is scattered throughout California to about 5900 feet ( 1800 m.! '' updates monthly and all other updates from time to time American settlers in the Asteraceae family in...