The Medicinal Uses of Spotted Knapweed

I usually leave the house only twice a week—once for the weekly shopping and on Sundays for church.  And on my way home one day, I noticed that the pasture was filled with lavender flowers.  I really wanted to find out what I was looking at.  I mean, it could be medicinal, right?  Becky’s got some handy app on her phone that identifies plants for her, and so I asked her to check it out.  And because she is into plants and natural medicine, she was happy to hop out. 

The flower in question turned out to be spotted knapweed (Centaurea biebersteinnii; formerly Centaurea stoebe L. ssp. micranthos).  Native to Eastern Europe, it was first reported in the US in 1893.[i]  So it naturally didn’t have any history of usage among Native Americans or any mention of usage in the US Pharmacopeia.  I’d never heard of it before.  None of my references had anything to say about it, but there were a bunch of references online.   So I was beginning to wonder:  Is this plant really medicinal, or is it a bunch of hype? 

Honestly, it’s hard to tell.  Here in the West, just don’t have the history for the usage of this particular species.  Often, but not always, the various species of a plant can be used interchangeably.  This is true of barberry and usnea.  It is not true of Potentilla (cinquefoil).  Spotted knapweed hasn't had any modern research conducted on it.  However, its relative, Centaurea calcitrapa, has been the subject of several studies.  Whether spotted knapweed possesses the medicinal qualities of Centaurea calcitrapa remains to be seen.

I don’t know about you, but I find the latest developments with the government and workplaces demanding COVID “vaccination” to be more than a little alarming.  Healthcare workers being fired for refusing the jab.  Communities mandating COVID passports for entering eateries.  The suggestion that healthcare be denied those who refuse the jab.  The idea that we could very well be all on our own for medical care in the near future doesn’t seem so far-fetched.  Throw in a little gas shortage or controls in how far we can travel, and we could well be limited to the medicinal herbs that grow in our own neighborhood.  So learning about lesser-known medicinal herbs, like spotted knapweed, may be a pretty good idea.

HARVEST

The leaves are harvested in the summer when the plant is in flower. 

PREPARATION

Studies on Centaurea calcitrapa indicated that the active constituents in the leaves are best extracted with a 70% alcohol solution.[ii]

EFFECTIVE AGAINST

• Candida albicans[iii]
• Escherichia coli[iv]
• Listeria monocytogenes[v]
• MRSA[vi]
• Staphylococcus aureus[vii]

MODERN USAGE

• Type-2 diabetes[viii]
• Wound healing[ix]

HISTORICAL USAGE[x]

• Circulatory
• Bleeding
• Communicable Disease
• Malaria
• Gastrointestinal
• Diarrhea
• Hemorrhoids
• Musculoskeletal
• Rheumatism
• Respiratory
• Cold
• Cough
• Fever
• Sore throat
• Skin
• Sores

OTHER USAGE

The flowers are edible.

 

 

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[i] Mark J. Renz, Spotted knapweed (Centaurea biebersteinnii), University of Wisconsin Extension, 16 July 2007, https://ipcm.wisc.edu/download/weeds/spotted_knapweed_WI.pdf (accessed 2 August 2021).

[ii] Ivica Dimkic, et al., New perspectives of purple starthistle (Centaurea calcitrapa) leaf extracts:  Phytochemical analysis, cytotoxicity, and antimicrobial activity, AMB Express, 12 October 2020, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7550514/ (accessed 2 August 2021).

[iii] Ivica Dimkic, et al., New perspectives of purple starthistle (Centaurea calcitrapa) leaf extracts:  Phytochemical analysis, cytotoxicity, and antimicrobial activity, AMB Express, 12 October 2020, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7550514/ (accessed 2 August 2021).

[iv] Ivica Dimkic, et al., New perspectives of purple starthistle (Centaurea calcitrapa) leaf extracts:  Phytochemical analysis, cytotoxicity, and antimicrobial activity, AMB Express, 12 October 2020, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7550514/ (accessed 2 August 2021).

[v] Ivica Dimkic, et al., New perspectives of purple starthistle (Centaurea calcitrapa) leaf extracts:  Phytochemical analysis, cytotoxicity, and antimicrobial activity, AMB Express, 12 October 2020, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7550514/ (accessed 2 August 2021).

[vi] Ivica Dimkic, et al., New perspectives of purple starthistle (Centaurea calcitrapa) leaf extracts:  Phytochemical analysis, cytotoxicity, and antimicrobial activity, AMB Express, 12 October 2020, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7550514/ (accessed 2 August 2021).

[vii] Ivica Dimkic, et al., New perspectives of purple starthistle (Centaurea calcitrapa) leaf extracts:  Phytochemical analysis, cytotoxicity, and antimicrobial activity, AMB Express, 12 October 2020, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7550514/ (accessed 2 August 2021).

[viii] Samaneh Fattaheian-Dekordi, et al., A review on anti-diabetic activity of Centaurea spp.:  A new approach for developing herbal remedies, Evidence-Based Complementary Alternative Medicine, 5 July 2021, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8275385/ (accessed 2 August 2021).

[ix] Dezso Csupor, et al., The traditional Hungarian medicinal plant Centaurea sadleriana Janka accelerates wound healing in rats, Journal of Ethnopharmacology, 8 January 2010, Vol 127 No 1, https://pubmed.ncbi.nlm.nih.gov/19799977/ (accessed 2 August 2021).

[x] Samaneh Fattaheian-Dekordi, et al., A review on anti-diabetic activity of Centaurea spp.:  A new approach for developing herbal remedies, Evidence-Based Complementary Alternative Medicine, 5 July 2021, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8275385/ (accessed 2 August 2021).

 09.03.23