Onopordum acanthium
Onopordum acanthium | |
---|---|
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Asterids |
Order: | Asterales |
Family: | Asteraceae |
Genus: | Onopordum |
Species: | O. acanthium
|
Binomial name | |
Onopordum acanthium |
Onopordum acanthium (cotton thistle,
It should not be confused with
Description
It is a biennial plant, producing a large rosette of spiny leaves the first year. The plants typically germinate in the autumn after the first rains and exist as rosettes throughout the first year, forming a stout, fleshy taproot that may extend down 30 cm (12 in) or more for a food reserve.
In the second year, the plant can grow to as much as 3 m (9.8 ft) tall with a width of up to 1.5 m (4 ft 11 in). The leaves are 10–50 cm (3.9–19.7 in) wide, alternate, spiny, and often covered with white woolly hairs with the lower surface more densely covered than the upper. The leaves are deeply lobed with long, stiff spines along the margins. Fine hairs give the plant a greyish appearance. The massive main stem may be 10 cm (3.9 in) wide at the base and branched in the upper part. Each stem has a vertical row of broad, spiny wings (conspicuous ribbon-like leafy material), typically 2–3 cm (0.79–1.18 in) wide, extending to the base of the flower head.
The
Distribution and habitat
The Cotton thistle is native to Europe and Asia. The plant prefers
In Europe, the plant tends to colonise disturbed pastures. In its native range, cotton thistle is considered a weak competitor that needs regeneration gaps to develop and maintain stands; populations tend to retreat when disturbance ceases.[8] The plant has been widely introduced at mid-latitudes across much of North America.[9]
Scotch thistles can spread rapidly. For example, it was first found in Utah in 1963. By 1981, it covered approximately 6070 hectares in 17 counties. Eight years later, it had spread to cover more than 22,540 hectares in 22 counties.[10]
Ecology
Onopordum acanthium reproduces by seeds only. Most seeds
The slender and smooth
The leaves of cotton thistle are eaten by the
Taxonomy and naming
Three subspecies are accepted:[4]
- Onopordum acanthium subsp. acanthium. Most of the species' range.
- Onopordum acanthium subsp. gautieri (Rouy) Franco. France, Spain.
- Onopordum acanthium subsp. parnassicum (Boiss. & Heldr.) Nyman. Greece.
The genus botanical name is derived from the Ancient Greek words όνος (ónos=donkey), πέρδω (pérdo=to fart), and άκανθος (ácanthos=thorn), meaning 'donkey fart thorny food'.[12][13][14]
The common name of cotton thistle refers to the
], not onopordum.Uses
It is grown as an ornamental plant for its bold foliage and large flowers.[16] It has been used to treat cancers and ulcers and to diminish discharges of mucous membranes. A recent study of a crude extract from the leaves of the plant demonstrated activity against glioblastoma, a type of very malignant brain tumor.[17] The receptacle was eaten in earlier times like an artichoke. The cottony hairs on the stem have been occasionally collected to stuff pillows. Oil from the seeds has been used for burning and cooking.[18][19]
Thistles produce abundant nectar for pollinators and provide seeds and floss for birds such as the goldfinch. Large-flowered tall thistles in particular provide considerable nectar.[20][21][22][23][24]
Invasive species
In the late 19th century, it was introduced to temperate regions of
In the United States, known infestations include most of the Pacific Northwest along with Utah, Colorado, New Mexico, Wyoming, Nebraska, and South Dakota. On western rangeland, infestations directly result in significant economic losses for ranchers. It is also widespread in Australia and New Zealand.[27] In Australia it commonly hybridises with the related invasive Onopordum illyricum.[26]
Control
- Mechanical
Small infestations may be physically removed or cut a few centimetres below the soil surface ensuring that no leaves remain attached to prevent regrowth. Mowing during early flowering will not kill the plant but will reduce seed production. Repeated treatments may be required because populations typically exhibit a wide range of developmental stages among individual plants. Slashing should be done prior to flowering since seed may mature in the seed head after cutting. Plants should not be mowed following seed set, as this increases chances for seed dispersal.[26][28]
- Chemical
Because of their shorter life cycle, cotton thistle plants can be effectively treated with herbicides. All herbicide treatments should be applied at the rosette stage of the plant. Generally, herbicide applications would be in early spring or autumn. One of the primary difficulties in chemical control of cotton thistles is their ability to germinate nearly year round. From autumn to spring a range of plant sizes can be found which may result in variable success from chemical control. Herbicides are very effective on seedlings and young rosettes, but control becomes more variable with increasing plant age. Onopordum spp. seeds may persist for several years in the soil. Buried seed may persist for up to twenty years, and reinfestation is likely without yearly management. Therefore, several years of re-treatment may be necessary. Picloram, dicamba, 2,4-D, dicamba + 2,4,-D, and metsulfuron are effective for controlling cotton thistle.[29] Clopyralid is more selective for controlling plants in the family Asteraceae, but will also injure or kill legumes.[26][28]
- Biological
There are no biological control agents that have been specifically released for cotton thistle control in the United States. A thistle head weevil Rhinocyllus conicus that feeds on Carduus pycnocephalus has also been shown to feed on cotton thistle. This insect was the object of imprudent biological control introduction, and it became an invasive species that has threatened endangered native thistles in North America (Strong 1997). Establishment of this thistle head weevil as a biological control agent for cotton thistle has been unsuccessful in the Pacific Northwest. A thistle crown weevil (Trichosirocalus horridus) that feeds on musk, bull, plumeless, Italian, and creeping thistles will also feed on cotton thistle. In Australia, this insect has been shown to kill cotton thistle rosettes. The related Trichosirocalus briese is also being tested as a control agent.[30] The Australian painted lady butterfly has been known to use this invasive species as a host plant, but the larvae do not do enough damage to the plant for this butterfly to be used as biological control agent.[31]
In Australia, a total of seven insects have been released to control cotton thistle.[32][33] Two of the seven released insects are weevils, including Larinus latus which feeds on the seeds, and Lixus cardui, which bores in the stems.[26][28]
- Integrated management
A combination of methods (IPM) is often more effective than any single method. An integrated pest management plan deals with prevention as well as control. Eradication of weed species is often not a practical goal, but in many cases reducing infestation to manageable levels is an achievable objective. Seed bank longevity is a major factor in managing cotton thistles. Re-establishing competitive perennial grasses and monitoring infested areas on a yearly basis is critical. Herbicides can successfully be used for reducing thistle populations and giving grasses a competitive advantage, but they cannot be used as a stand-alone solution. These techniques must be linked with good grazing practices in rangeland areas. Otherwise, the thistles will recolonize and rapidly replenish the seed bank to pre-control levels.[26]
References
- ^ ISBN 978-0-521-70772-5.
- ^ Den virtuella floran: Onopordum acanthium (in Swedish, with maps)
- ^ Europaea: Onopordum acanthium [dead link]
- ^ ISBN 0-521-08717-1
- ^ Flora of NW Europe: Cotton Thistle[permanent dead link]
- ^ Young, J.A. and R.A. Evans. 1969. "Control and ecological studies of Scotch thistle". Weed Science 17:60-63.
- JSTOR 2260503.
- S2CID 35269104.
- ^ Taylor, R. J. 1990. "Northwest Weeds: The Ugly and Beautiful Villains of Fields, Gardens, and Roadsides". Mountain Press Publishing, Missoula, Montana.
- ^ Dewey, S.A. (1991). Weed thistles of the western United States. In: James, L. F., J. O. Evans, M. H. Ralphs, and R. D. Child, eds. Noxious Range Weeds. Westview Press, Boulder, Colorado, pp. 247-253.
- S2CID 83133668.
- ^ Bill Thayer, Pliny the Elder: the Natural History, Liber XXVII
- ^ Pline l'Ancien, Histoire Naturelle, Tome second, Livre XXVII, Traduction française: É. Littré
- ^ Vaillant S., Etablissement de nouveaux caractères de trois Familles ou Classes de Plantes à Fleurs composées, à savoir des Cynarocéphales..., Histoire de l'Academie Royale des Sciences. Avec les Mémoires de Mathematique & de Physique, Paris 4,: 152, 1718
- ^ "Onopordum acanthium". Germplasm Resources Information Network. Agricultural Research Service, United States Department of Agriculture. Retrieved 18 December 2017.
- ISBN 0-88192-699-X
- ^ Abusamra YA et.al., 2015. Evaluation of putative cytotoxic activity of crude extracts from Onopordum acanthium leaves and Spartium junceum flowers against the U-373 glioblastoma cell line. Pak J Pharm Sci. 2015 Jul;28(4):1225-32.
- ^ Henriette's Herbal: Onopordum acanthium
- ^ M. Grieve (1971). A Modern Herbal: The Medicinal, Culinary, Cosmetic and Economic Properties, Cultivation and Folk-Lore of Herbs, Grasses, Fungi, Shrubs & Trees with Their Modern Scientific Uses. New York: Dover Publications.
- ^ Eckberg, James; Lee-Mäder, Eric; Hopwood, Jennifer; Foltz Jordan, Sarah; Borders, Brianna (2017). "Native Thistles: A Conservation Practitioner's Guide". The Xerces Society. The Xerces Society. Retrieved 27 August 2018.
- ^ "Which flowers are the best source of nectar?". Conservation Grade. 15 October 2014. Archived from the original on 14 December 2019. Retrieved 18 October 2017.
- PMID 27341588.
- ^ "Pasture Thistle". Illinois Wildflowers. Dr. John Hilty. Retrieved 27 August 2018.
- ^ "Bull Thistle". Illinois Wildflowers. Dr. John Hilty. Retrieved 27 August 2018.
- ^ CAB International. "Crop Protection Compendium, 2004 edition". CAB International, 2004. Archived from the original on 16 July 2007.
- ^ a b c d e f Global Invasive Species Database: Onopordum acanthium
- ^ Tamar Valley Weed Strategy: Cotton Thistle
- ^ a b c Cotton Thistle (Onopordum acanthium L.) Control Guide
- ^ Beck, K.G. (1991). Biennial thistle control with herbicides. In: James, L.F., J.O. Evans, M.H. Ralphs, and R.D. Child, eds. Noxious Range Weeds. Westview Press, Boulder, Colorado. pp. 254-259.
- JSTOR 827177.
- .
- S2CID 85383089.
- ^ Swirepik, A., Smyth, M., 2002. Biological control of broad-leafed pasture weeds (Paterson's curse, Onopordum and nodding thistles): what have we achieved and where to from here?. In: Spafford J.H., Dodd, J., Moore, J.H. (Eds.), Proceedings of the 13th Australian Weeds Conference, Plant Protection of WA, Perth, pp. 373-376.
Further reading
- Donald R. Strong (1997). "Fear no weevil?". S2CID 83205230.
- Gianfranco Tucci; Marco Cosimo Simeone; Carlo Gregori; Fabio Maggini (1994). "Intergenic spacers of rRNA genes in three species of the Cynareae (Asteraceae)". S2CID 26309594.
External links
- Species Profile - Scotch Thistle (Onopordum acanthium), National Invasive Species Information Center, United States National Agricultural Library. Lists general information and resources for cotton thistle.