Chapters 6.12
6.12 -Thistle (Cirsium species)
Gavin Bouwman, University of Guelph, Canada
Suggested citation for this chapter.
Bouwman, G. (2022) Greens, Fleshy Stems and Gourds. In The Student Encyclopedia of Canadian Indigenous Foods. Editor, M.N. Raizada, University of Guelph, Canada. http://www.firstnationsfoods.org/
Introduction
In nature there are so many plants that people are misinformed about and don’t know what each plant can do, thistles are one of those plants seen as just a weed with spikes that hurt. The thistle is an edible plant that was used often in the past by indigenous people and still is used in the present. In this report the objective is to evaluate the future of thistles as a product. Throughout this report the thistle will be researched in areas such as basic information and the indigenous history of uses of the thistle. The effects and benefits that consuming thistle will have on humans and on animals will be discussed. The environmental limitations of the plant can be researched to see how the plant affects surrounding areas and to see if it affects anything negatively. The sustainability of the plant and how that is the key to the plant being marketable and the marketing limitations that may face the plant. The importance of marketing thistles and how successful the plant is as a herbal medicine and what future studies could be done for the plant
Basic information
The thistle is a plant that grows 5-10 feet and has prickly edged leaves and a purple flower head that can be quite sharp (“Milk Thistle”, 2012). The leaves at the top of the plant gradually get smaller and narrower with shallower lobed or smooth edges the closer to the top they get shown in figure 1 (Kuhnlein and Turner, 1991). Thistles are one of the most invasive plants in the world (Guggisberg et al, 2012). The Canada thistle which is the most common thistle in Canada can be found in every province in Canada in areas that have been colonized (Guggisberg et al, 2012). The Canada thistle despite the name is not from Canada and is believed to be from the Mediterranean regions (“Canada Thistle”, 2021). It got the name Canada thistle because the USA blamed French Canadian traders for the emergence of that kind of thistle in the USA and in their fields although historians believe it showed up in Canada at the same time (“Canada Thistle”, 2021).
Thistles typically grow in open areas, including pastures, cultivated fields, logged forests, riverbanks and roadsides (“Canada Thistle”, 2021). The thistle does not like wet areas and thrives on direct sunlight and is a drought tolerant plant (“Canada Thistle”, 2021). Thistles are perennial, meaning that they can grow back year after year if the roots are not pulled out (Kuhnlein and Turner, 1991). Since it is a perennial and very invasive it is very hard to get out of fields even when it is plowed up, the roots are still intact and will grow again the next growing season (Guggisberg et al, 2012). The thistles start to emerge from the soil in April and will continue to do so all summer long (“Canada Thistle”, 2021). The seeds begin to germinate in late May and continue through to autumn and a single plant can produce around 1000-1500 seeds, which are mostly dispersed by wind but can be moved by animals, equipment, clothing, water and vehicles (“Canada Thistle”, 2021).
Indigenous history
What drew indigenous groups to the use of thistles once they knew it was not poisonous was how easy it was to go out and harvest large amounts very quickly (Timoney, 2018). Every part of the plant is edible (“Canada Thistle”, 2021). The leaves had to have the spikes removed from them before eating which, was done by cutting or pulling them out (“Canada Thistle”, 2021). The young shoots of the thistle would be considered in many ways like asparagus so it could be eaten fresh or cooked (Timoney, 2018). The younger shoots were better before the plant got too big and the stem would get barky (Timoney, 2018).
There are many indigenous groups that used Milk Thistles and the Canada Thistle for medical use to help liver problems and attempts to cure cancers as well as the infusion of its roots for mouth diseases (Ephel and Sherman, 2019). The Ojibwe people used the root of the thistle to help with stomach cramps (Ephel and Sherman, 2019). The Ojibwe people also used the root as a bowel tonic and a diuretic (Smith, 1932). Bowel tonic helps to improve the bowel motility and lower tonicity in the bowel (Smith, 1932). A diuretic helps to rid the body of salt and water as well as is most helpful to the liver (Smith, 1932).
Navajo used the thistles to induce throwing up and to protect the liver against toxins as well to treat chronic liver disease (Ephel and Sherman, 2019). The Navajo people also would use thistles to treat hepatitis, cancer prevention and high cholesterol (Turner and Von Aderkas, 2012). The thistle was given many nicknames by the Navajo people such as Mary Thistle and Holy Thistle (Turner and Von Aderkas, 2012). The thistle was not only just a medicine, as many indigenous groups would consume thistles in different ways including putting the leaves in a salad, soup and teas (Timoney, 2018). Thistles were consumed as a regular food when used as a medicine, one of the ways it was consumed would be using the roots in a hot soup or stew (Kuhnlein and Turner, 1991).
When thistles are boiled the roots taste sweet and there was lots of different ways it could be consumed for use as a medicine (Kuhnlein and Turner, 1991). The seeds at maturity were also used for medicine since it collected curdled milk inside it which helped with various illnesses (Kuhnlein and Turner, 1991). The Shuswap people of British Columbia would eat the roots raw since the thistle has a taproot or would cook it with meat (Kuhnlein and Turner, 1991). They would also eat the fresh flower of certain types of thistles such as white thistle or hooker thistle (Kuhnlein and Turner, 1991).
Effects on humans
The Milk Thistle have been used for a very long time because it contains silymarin which helps medically (Post-White et al, 2007). Silymarin is mainly used as a treatment for liver and biliary disorders but is not approved by US food or drug administration (Post-White et al, 2007). Biliary disorders are diseases affecting the gallbladder (Post-White et al, 2007). Bile ducts and other structures, bile is produced in the liver and aids in digestion (Post-White et al, 2007).
The Canada Thistle also contains inulin which is a polysaccharide which helps lower levels of blood sugar and is perfect for people with diabetes (Carballido, 2021). Eating thistles can be very healthy for the body and can be used for things like fluid retention, obesity, kidney stones and more (Carballido, 2021). Thistles are rich in acids, cynarine and calcium which are the main components for increasing urine output (Carballido, 2021). It is a good diet food since it is low in calories and has a very high percentage of water as seen in table 1, but it does have an excess amount of sodium (salt) which is not good in large amounts (Carballido, 2021). To counter the level of sodium, the thistle is very high in the levels of potassium (Carballido, 2021).
Effects on animals
There have been experiments on feeding thistles (pills) to rabbits to see if they can cure or treat diabetes with the Canada Thistle as it has inulin in the plant (Shakeel et al, 2014). The results showed that the milk thistle positively affected the rabbits and helped make them healthier (Shakeel et al, 2014). In the wild animals will eat the flowers off the thistles but nothing else since the thistles have physical defences such as spikes on their leaves (Timoney, 2018).
,p>This defence in thistles minimizes energy costs and maximizes protection (Timoney, 2018). Thistles are very important to honeybees, birds and insects as they have a large amount of nectar and pollen (Turner and Von Aderkas, 2012).
Environment limitations
The thistle can be found in basically all crop fields and negatively affect the yield of the crop plants such as canola, wheat and barley (“Canada Thistle”, 2021). The thistle is found in the crops when harvested which will have to be taken out (“Canada Thistle”, 2021). The use of herbicides on thistles is not one hundred percent effective but is helped if the plant is under a great amount of stress (“Canada Thistle”, 2021). Events that may stress the plant and cause the herbicides to be more effective are floods, drought, cold temperatures and harsh winters (“Canada Thistle”, 2021). Since the plant mainly spreads through the roots, control methods would have to focus on clones and for this reason there are currently no appropriate control techniques for widespread removal in natural areas (“Canada Thistle”, 2021). In Canada the Canada thistle is labeled as a noxious plant which means it is harmful to crops and/or natural areas (“Canada Thistle”, 2021).
References
1.Canada thistle. NCC. (2021).
2. Cai, C., & Castelino-Prabhu, S. (2019). Thistle Plant. Thistle Plant - an overview | ScienceDirect Topics. Retrieved November 27, 2021, from https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/thistle-plant.
3. Carballido, E. (2021, June 29). Thistle Nutrition. Botanical online. Retrieved November 23, 2021, from https://www.botanical-online.com/en/food/thistle.
4. Ephel, T. J., Sherman, P. G. (2019). Cirsium arvense: Canada Thistle. alternative weed control, history and uses. Canada Thistle or Creeping Thistle. Retrieved from https://www.wildflowers-and-weeds.com/weedsinfo/Cirsium_arvense.htm.
5. Guggisberg, A., Welk, E., Sforza, R., Horvath, D. P., Anderson, J. V., Foley, M. E., & Rieseberg, L. H. (2012). Invasion history of North American Canada Thistle, cirsium arvense. Journal of Biogeography, 39(10), 1919–1931.
6. Kuhnlein, H. V., & Turner, N. J. (1991). Traditional Plant Foods of Canadian Indigenous Peoples: Nutrition, botany and use. Gorden and Breach.
7. Milk Thistle. Agriculture and Forestry: Pest Selector. (2012). Retrieved, from http://www.agric.gov.ab.ca/app107/loadPest?action=display&id=69.
8.Post-White, J., Ladas, E. J., & Kelly, K. M. (2007). Advances in the use of milk thistle (silybum marianum). Integrative Cancer Therapies, 6(2), 104–109. Retrieved from https://doi.org/10.1177/1534735407301632.
9. Shakeel, Hafiz, A., Yar, & Karim, A. (2014). Effect of milk thistle (Silybum Marianum) plant parts (seeds and leaves) to control the alloxan induced diabetes in rabbits. ProQuest. Retrieved from https://www.proquest.com/publiccontent/docview/1503097399?pq-origsite=primo&accountid=11233.
10.Smith, H. H. (1932). Ethnobotany of the Ojibwe Indians. In Bulletin of the Public Museum of the City of Milwaukee (Vol. 4, pp. 327–525). essay, Order of the Board of Trustees.
11. Timoney, K. (2018). The Holy Grail of Wild Foods? How to Gather, Prepare, and Enjoy Eating Canada Thistle. Retrieved from https://anpc.ab.ca/wp-content/uploads/2015/01/Thistle.pdf.
12.Turner, N. J., Von Aderkas, P. (2012). Sustained by First Nations: European newcomers' use of indigenous plant foods in temperate North America. Acta Societatis Botanicorum Poloniae, 81(4), 295–315. https://doi.org/10.5586/asbp.2012.038.
13.U.S. Department of the Interior. (2020). Invasive plant profile: Canada and Bull Thistles (U.S. National Park Service). National Parks Service. Retrieved November 21, 2021, from https://www.nps.gov/articles/000/canada-and-bull-thistles-acadia.htm.