"star thistle." YourDictionary, n.d. Web. 12 November 2018. <https://www.yourdictionary.com/star-thistle>.
star thistle. (n.d.). Retrieved November 12th, 2018, from https://www.yourdictionary.com/star-thistle
Any of several plants of the genus Centaurea of the composite family that have spiny yellow or purplish flower heads, especially C. solstitialis, native to Eurasia and widely naturalized in North America.