any of several naturalized Eurasian plants of the genus Centaurea, especially C. calcitrapa, having purplish, spiny flower heads.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Word Origin for star thistle
C16: so called because it has a thistle-shaped flower surrounded by radiating spines
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012