Scotch Thistle Identification and Management 2015 Quarter Quad Survey Leslie Mehrho niversity o CT onnie illion PS onnie illion PS. The leaf margins of a flowering bull thistle plant (a) are tipped with spines, and the stems have spiny wings. Onopordum illyricum - Illyrian Scotch Thistle. General. Scotch thistle is a prolific seed producer. Bull thistle, while common throughout Wisconsin, rarely forms large populations, but none the less can be problematic. Less than twenty percent of the seeds initially produced are ready to germinate. It's almost impossible to misidentify a thistle. Leaves are oblong and prickly with toothed margins. National Invasive Species Information Center, Early Detection & Distribution Mapping System (EDDMapS) - Scotch Thistle, YouTube - Weed of the Week: Scotch Thistle, Factsheet - Scotch Thistle (Mar 2017) (PDF | 968 KB), Invasive Plant Atlas of the United States - Scotch Thistle, Weed Control in Natural Areas in the Western United States: Scotch Thistle (2013) (PDF | 262 KB), Noxious Weed Information - Scotch Thistle. Phylum: Magnoliophyta - Class: Equisetopsida - Order: Asterales - Family: Asteraceae This tall member of the Daisy family is found throughout the Iberian Peninsula and eastwards as far as the Balkans. Uses and Values: Plumeless thistle is an important plant for bu ©er-flies. Figure 2C. Scientific Name: Onopordum acanthium L. ( ITIS) Common Name: Scotch thistle, cotton thistle, heraldic thistle, woolly thistle. Rosettes can grow up to 2 feet in diameter and mature plants are up to 6 feet tall. Flower heads of the invasive thistles present in Oklahoma musk thistle (top left), bull thistle (top right), Canada thistle (bottom left) and Scotch thistle (bottom right). Pacific Northwest Extension. Poisoning: Plumeless thistle may accumulate nitrates, but it is unpal-atable to livestock. This thistle, Cirsium altissimum, has pointed leaves with spines growing along the leaf margins. Scotch thistle is a plant. Onopordum acanthium. * Entire lengths of stems have spiny wings, becoming broad and spiny. How Does it Reproduce? Each thistle plant can produce up to 40,000 seeds. University of Idaho; Oregon State University; Washington State University. General. General: Scotch Thistle is considered a biennial herb, but it can behave like an annual or a short-lived perennial depending on the conditions. * Foliage is silvery gray and can grow taller than 6 feet. (2013). YouTube; University of Arizona. Scotch thistle is a large biennial thistle. This site is also protected by an SSL (Secure Sockets Layer) certificate that’s been signed by the U.S. government. References. and Their Identification Case Medlin Assistant Professor and Extension Weeds Specialist Ronald J. Tyrl Professor of Botany In 1994 a Thistle Law, was enacted in four counties in northeastern Oklahoma. Scotch Thistle. Use a chemical weed solution if this thistle isn't easy to manually control. Figure 2A. Our program staff can provide the property owner or appropriate public agency with site-specific advice on how best to remove it. Scotch thistle can be confused with bull thistle (Cirsium vulgaris), which is also sometimes called "Scotch thistle" and is much more common in western Washington. Program offices are located at 201 S. Jackson St., Suite 600, Seattle, WA 98104. It spreads by seed and generally inhabits moist sites or drainages in dry locations. Which is the true Scotch Thistle even the Scottish antiquarians cannot decide, but it is generally considered to be this species of Thistle that was originally the badge of the House of Stuart, and came to be regarded as the national emblem of Scotland. Scotch thistle was introduced into the United States from Europe. Victoria Department of Jobs, Precincts and Regions (Australia). Kyser et al. Scotch thistle was once an ornamental plant, rich with symbolism, but is now considered an invasive weed. Noxious Weed Identification; Scotch Thistle; Scotch Thistle Scotch Thistle. The plant forms dark pink to purple, globe-shaped flower heads, 1-2 inches in diameter, which stand alone on branch tips and bloom July-October. Scotch thistle is similar in appearance to other Onopordum species, in particular Illyrian thistle (Onopordum illyricum). Scotch thistle, Gary Stone photo. Native To: Eurasia ( Briese et al. Scotch thistle(Onopordum acanthium) invaded Okla- homa from the west. People take Scotch thistle to stimulate the heart.. Be careful not to confuse Scotch thistle with similar sounding natural medicines such as milk thistle or Scotch pine needle. Seeds spread by wind, water, animals, clothing, and also in hay. Leaves: Upper surfaces of leaves are green, and the lower surfaces Other: Plumeless thistle is an aggressive weed and is similar to the closely related musk thistle. Or, to display all related content view all resources for Scotch Thistle. Scotch thistle is a prolific seed producer. Use a chemical weed solution if this thistle isn't easy to manually control. Gray-green, woolly, spiny leaves reach up to 2 feet long and 1 foot wide. Each thistle plant can produce up to 40,000 seeds. In contrast musk thistle is more common in southern Wisconsin, but populations have been spreading north. Scotch, Illyrian and nodding thistles: Plant: begins as a rosette, develops into a single or multi-stemmed biennial herb, height varies from 30cm to 2m according to conditions and species Leaves: the rosette leaves are deeply lobed, long spines cover the leaf margins and stems, Scotch thistle has a distinctive covering of dense white Before sharing sensitive information online, make sure you’re on a .gov or .mil site by inspecting your browser’s address (or “location”) bar. Identification tips Scotch thistle is often mistaken for other thistles, particularly spear thistle. This plant reproduces by seed. 2003. Thistle Identification By Deborah Ng Updated June 8 ... Scotch thistle was once an ornamental plant, rich with symbolism, but is now considered an invasive weed. The weed is a prolific seed producer, with an average of 200 seeds per seedhead, and individual plants can produce over 50,000 seeds. Flowers are purple or white and disc shaped. Scotch thistle florets are purple or mauve in heads surrounded by numerous spiny bracts (modified leaves at the base of flower). Kyser et al. Maps can be downloaded and shared. Scotch thistle is a prolific seed producer. Best offers for your Garden - https://amzn.to/2InnD0w Thistle Identification. Scotch thistle has large broad leaves. However, it is the only thistle species is New Zealand which has spines on the foliage on the surface of leaves in addition to around the leaf margins (see lower photo). It is much more common in counties on the east side of the Cascades. The https:// means all transmitted data is encrypted — in other words, any information or browsing history that you provide is transmitted securely. Figure 2B. For more information on noxious weed regulations and definitions, see Noxious weed lists and laws. In 1994 a Thistle Law, was enacted in four counties in northeastern Oklahoma. The section below contains highly relevant resources for this species, organized by source. Scotch thistle is the most well-armed plant you will find outside of the deserts of the American southwest. Scotch thistle is more densely covered with white hairs, tends to be taller, and the stems have "wings" along the entire length, unlike bull thistle. Positive identification of a Scotch thistle is easy – the sharp-edge, hairy leaves are a dead giveaway. Scotch thistle has been found growing in a number of western Washington counties but the sites are generally small and isolated. See also: Included on California's noxious weed list; see. Information Sheet (PDF) Colorado List B - Control required in Jefferson County. Scotch thistle will grow in wet meadows and pastures as well as dry pastures and rangelands. Cooked milk thistle leaves make a superb substitute for spinach. Scotch thistle has large broad leaves. It rarely reaches infestation levels that justify treatment, probably because the insects that feed on native Circium spp. It is also known as Onopordum acanthium and can be either and annual or a biennial plant. The root systems explain why; spear thistle has a tap root, whereas creeping thistle grows on rhizomes. The leaves are long and large (up to 18 inches in length), and they are bluish-grayish green in color and covered with fine hairs. The majority of Scotch thistle infestations in Washington occur in eastern Washington. Scotch thistle is an erect annual or biennial herb to 2 m high, commonly 1 to 1.2 m. Generally one main stem with numerous branches, covered with dense, appressed, woolly hairs giving it a whitish-grey appearance. Washington State Noxious Weed Control Board. The leaves are long and large (up to 18 inches in length), and they are bluish-grayish green in color and covered with fine hairs. To fi nd this weed you will need to become familiar with a few key identifi cation features described below. bull thistle), or more broad and triangular (e.g. California Department of Food and Agriculture. Scotch thistle can grow to a height of from 3 to 9 feet. Scotch thistle in a pasture Early Detection and Rapid Response (EDRR) is a concept to identify potential invasive species prior to or just as the invasive is becoming established. Another noxious thistle, it has large, spiny leaves and flowers, which turn reddish-purple. Washington Invasive Species Council. Also, because Scotch thistle is not established in King County, we have an opportunity to stop it from spreading if we act quickly. With its long roots, Scotch thistle is hard to remove completely. As with most thistles, Scotch thistle has a tap-root. It emerges as a rosette, before bolting and producing seeds in a subsequent season. During the first year of growth, Scotch thistle appears as a rosette in spring or fall. University of Western Ontario, London, Canada. Scotch Thistle … Scotch thistle (Cirsium vulgare) is one of the most common thistle weeds in New Zealand, being present in all regions of the country in a diversity of habitats. Bull thistle, while common throughout Wisconsin, rarely forms large populations, but none the less can be problematic. Onopordum acanthium. Amended in 1995, 1998, and 1999, it now declares musk, scotch, and Canada thistles to be noxious weeds and public nuisances in all counties of the state. Biennial; Family: Sunflower (Asteraceae) Native to Europe and eastern Asia; Habitat. Biennial; Family: Sunflower (Asteraceae) Native to Europe and eastern Asia; Habitat. Scotch Thistle Fact Sheet. Measure It is also known as Onopordum acanthium and can be either and annual or a biennial plant. We map all known locations of regulated noxious weeds such as Scotch thistle in order to help us and others locate new infestations in time to control them. Scotch thistle differs from bull thistle as it has larger yet fewer flowerheads, lacks basal leaves and has dense woolly hairs on its leaves; giving it a silvery appearance. Scotch thistle is a Class B noxious weed and control is required in King County. An Integrated Pest Management plan (IPM) can be developed to manage, contain and eradicate the invasive species before it can spread further. Weed Control in Natural Areas in the Western United States [PDF file].Weed Research … Tall Thistle. Infestations of Scotch thistle reduce forage production and virtually prohibit land utilization for livestock Qaderi MM, 1998. Stems are coarse with many spines, and are gray-green and highly branched. It reproduces/spreads from seed. Measure whether bracts collectively are greater than or less than 0.8 inches high, referring to the white bracket in Figure 2 for the length to measure. Qaderi MM, 2002. 2003) Date of U.S. Introduction: 1800s ( … Speaking of the Southwest, it is considered an invasive in the Grand Canyon . Parts of the plant can break off causing vegetable fault and thus a loss in v… It can also be found in over-grazed sites, roadsides, and riparian areas. Provides state, county, point and GIS data. whether needle-like (e.g. History, Distribution and Identification longitudinally) with spiny 'wings' originating where the edges of the leaves continue down the stem. But farmers should make sure they are sure of the identification of the thistles in their paddocks before they decide on the herbicide to use. musk thistle) is important for identification. You can identify the Scotch thistle, Onopordum acanthium, by its hairy, greyish blue foliage. Google. Flower: Irregularly round, purple, thistle-like flowers growing on a rigid stems to 1m tall . Figure 2. CA-County Noxious Weed Project List (Scotch thistle) (ONAC) CO-Douglas County Weed Education (ONAC) Canada-Ontario Noxious Weeds (ONAC) Idaho One Plan: noxious abstract & images (ONAC) Invasive Plant Atlas of New England (ONAC) NV-Extension Weed Wanted Posters (ONAC) OK-OSU Extension-Thistles and their Identification (ONAC) Scotch thistle, initial bolt stage, Gary Stone Photo. MSc thesis. Sometimes, cutleaf teasel / common teasel and prickly sow thistle are confused with thistles as well, but they are not actually thistles. Scotch thistle reproduces by seed. Scotch thistle is a non-native biennial forb but can behave as an annual or short-lived perennial. Scotch thistle closely resembles the wavy-leafed thistle (Cirsium undulatum), but the native thistle is typically smaller (it does not exceed 1.2 m), and basal leaves are considerably smaller (3.0-7.0 cm long). Its seeds are eaten by numerous species of songbirds. The flower head is distinctive, being smaller than heads of nodding thistle (Carduus nutans) and variegated thistle (Silybum marianum), and larger than heads of Californian thistle (Cirsium … Tasmania, Victoria and New South Wales)." Thistles compete with pastures and reduce their carrying capacity. Creeping thistle will grow in all manner of waste-ground, grasslands, verges and field edges. National Genetic Resources Program. Noxious Weed Identification; Scotch Thistle; Scotch Thistle Scotch Thistle. Onopordum acanthium. Severe infestations can form tall, dense, impenetrable stands, especially in fertile soils. Flower heads are 1-3 inches in diameter and are solitary or in clusters of up to 7. The authors describe the diversity of the 62 species of native thistles in North America, showcasing several species from different regions. With its long roots, Scotch thistle is hard to remove completely. Thistles identificationn Thistles are erect flowering plants that typically stand around 2 m in height, with spiny leaves and stems. Coconino County Cooperative Extension. Infestations have occurred primarily in Roger Mills and Custer counties since the early 1990s; but in 1999-2000, new infestations were recorded in Love, Texas, Harper, and Woodward counties. It is a vigorous biennial plant with coarse, spiny leaves and conspicuous spiny-winged stems. Australian Government. It is native to Europe and Western Asia from the Iberian Peninsula east to Kazakhstan, and north to central Scandinavia, and widely naturalised elsewhere, with especially large populations present in the United States and Australia. Dense stands of mature thistles create barriers that hinder livestock movement. In comparison, bull thistle has basal leaves and leaves that are smooth to sparsely woolly below; giving a green appearance. Rosettes of leaves can reach up to six feet across and stems may grow from six to eight feet tall. Center for Invasive Species and Ecosystem Health. Flowers: Are vibrant purple and grow at the end of leafy stalks, as a single flower or a cluster of flowers. Each thistle plant can produce up to 40,000 seeds. Colorado Department of Agriculture. Native versus Exotic (Source: Parkinson and Mangold 2015) Positive identification of a Scotch thistle is easy – the sharp-edge, hairy leaves are a dead giveaway. Invasive Species Council of British Columbia (Canada). Identifying thistles. The breathtaking globe-shaped purple flowers are loved by many, but the seeds they produce can survive in the soil for up to 20 years. Most King County offices will be closed on December 25, for Christmas Day. This species is also on the Washington quarantine list (known as the prohibited plants list) and it is prohibited to transport, buy, sell, offer for sale, or to distribute plants or plant parts, seeds in packets, blends or "wildflower mixes" of this species, into or within the state of Washington. Scotch thistle is a non-native biennial forb but can behave as an annual or short-lived perennial. thistles also feed on bull thistle. The rest only have spines around the margins. USDA. The tall statuesque stems of this native Scotch thistle are clad in silvery spiny foliage and topped with a huge pink thistle. Scotch thistle (Onopordum acanthium) is a native of Europe and eastern Asia and is probably an escaped ornamental. University of Georgia. Noxious Weed Program. Layer chromatography-bioassays directed screening and identification of antibacterial compounds from Scotch thistle. Scotch Thistle – Onopordum acanthium, exotic and undesirable * Receptacle of flower head has no bristles. Scotch thistle has been found growing in a number of western Washington counties but the sites are generally small and isolated. Habitat. Weed Control in Natural Areas in the Western United States [PDF file].Weed Research … Left: Bull thistle, page 5 photo by Starr Environmental, bugwood.org Right: Flodman’s thistle, page 12 photo by M. Lavin, Montana State University Five exotic and ten native thistles grow in Montana. It is very difficult to eradicate. Onopordum acanthium (cotton thistle, Scotch (or Scottish) thistle) is a flowering plant in the family Asteraceae. Spear thistle (Cirsium vulgare) is regarded as an environmental weed in parts of south-eastern Australia (i.e. Scotch thistle, generally found along the Platte River in western Nebraska, also can be found in poorly managed pastures. Agriculture. Thistles of Nebraska Flodman Thistle Cirsium flodmanii (Rydb. Become a certified small business contractor or supplier, Find certified small business contractors and suppliers, Washington State Noxious Weed Control Board. Scotch thistle have large spiny leaves that are covered in fine hairs. To many, thistle is considered an invasive weed. Scotch thistle, cotton thistle, heraldic thistle, woolly thistle. Scotch Thistle: Options for Control Lincoln County Noxious Weed Control Board. GRIN-Global. DiTomaso, J.M., G.B. ARS. Scotch thistle can grow to a height of from 3 to 9 feet. References. Bull thistle (Cirsium vulgare) (Figure 2) has been present in Oklahoma for more than 40 years and occurs statewide. Conservation Services. 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 New South Wales Department of Primary Industries (Australia). Infestations have occurred primarily in Roger Mills and Custer counties since the early 1990s; but in 1999-2000, new infestations were recorded in Love, Texas, Harper, and Woodward counties. Photo: Steve Dewey, Utah State University, Bugwood.org . Scotch Thistle Noxious Weed Control Board, Washington State. Department of the Environment and Energy. It is used as medicine. Móricz ÁM, Krüzselyi D, Alberti Á, et al. Scotch thistle is a non-native biennial forb but can behave as an annual or short-lived perennial. The .gov means it’s official.Federal government websites always use a .gov or .mil domain. Cooked flower buds have a slightly sweet taste, and are delicious when brewed into a tea. To contact staff, see the Noxious Weed Control Program Directory, send an email, or call 206-477-WEED (206-477-9333). Bull thistle gene… * Montana has only 1 species. Conservation Services Division. Scotch Thistle. In mid-summer, 2-inch-wide, dark pink to lavender, globe-shaped flower heads appear in groups of 2 or 3 at stem ends. Native Thistles: A Conservation Practitioner’s Guide is packed with resources and information on the natural history and ecology of native thistle species. Rosette leaves smother desirable pasture species in spring reducing their early growth. Scotch Thistle A weed report from the book Weed Control in Natural Areas in the Southwestern United States, 2013, DiTomaso, J.M., G.B. Washington State Recreation and Conservation Office. Scotch Thistle (Onopordum acanthium) Identification. J Chromatogr A. Briese, D.T., S. Bottcher, J. Vitou, and T. Thomann. Kyser et al. Scotch thistle, a regulated Class B noxious weed, is an annual or biennial that grows 8 feet tall in meadows, pastures, and other habitats. Onopordum acanthium (Scotch thistle) is a biennial or short-lived perennial (family Asteraceae) which is primarily found in the northeastern regions of California. It may also be found alongside streams and rivers. Please click here to see a county level distribution map of Scotch thistle in Washington. Scotch Thistle Fact Sheet. Onopordum acanthium (cotton thistle, Scotch (or Scottish) thistle) 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, with especially large populations present in the United States and Australia. Please report them if you think you have them. It is much more common in counties on the east side of the Cascades. of an individual thistle bract, e.g. Scotch thistle is found in any type of habitat but normally establishes quickly in disturbed areas dominated by annual plants such as cheatgrass. Bracts are woolly at the base and end in orange spines. Weed Research and Information Center. Scotch Thistle. Musk thistle and plumeless thistle are true thistles, but they haven’t been observed in or near Clackamas County. Milk thistle plant parts can be eaten either cooked or raw – with the exception of the need to boil the leaves to remove their prickles. I also see a lot of spear thistle in similar habitats, although when found in grassland, it's not as abundant as the creeping species. These three species are common to pastures and right of way areas, but have become more common in no-till fields over the past decade. Identification –5. Identify Scotch thistle by its rich purple blooms and the thick, spiky hairs on its leaves. Scotch thistle Identification and Management Scotch thistle (Onopordum acanthium) is a non-native biennial forb that reproduces solely by seed. Genera in the Asteraceae with the word thistle often used in their common names include: Scotch thistle stands are dense and practically impenetrable due to the weed's spiny nature and large size. Pre- and post-dispersal factors affecting cypsela dormancy in Scotch thistle, Onopordum acanthium (Asteraceae). Scotch thistle seem to be susceptible to MCPB and 2,4-DB, both of which will kill Scotch thistles without damaging clovers, So far no resistance to these herbicides has been found in New Zealand. Scotch thistle ( Onopordum acanthium) is a biennial or perennial plant that can form dense, inpenetrable stands and competes with field crops and forage plants. University of California. Stems have ribbon-like, spiny "wings." DiTomaso, J.M., G.B. Scotch thistle can be confused with bull thistle (Cirsium vulgaris), which is also sometimes called "Scotch thistle" and is much more common in western Washington. However, not all species of thistle are noxious weeds. Scotch thistle. It reproduces/spreads from seed. 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. The Conservation Services Division provides technical and financial support, leadership and statewide coordination, and regulatory oversight to public/private landowners and agricultural businesses statewide on an array of natural resource management challenges. Stem and leaves "The stems are ridged lengthwise (i.e. One of the easy-to-spot botanical differences between thistles and their numerous relatives in the daisy family, is that the overlapping bracts (involucre) found directly below the flowers of thistles, are always spiny. Weed Research and Information Center, University of California Before bolting and producing seeds in a subsequent season by an SSL ( Secure Sockets Layer ) certificate ’... 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Are noxious weeds: Plumeless thistle is often mistaken for other thistles particularly.