The spiny foliage suggests a true thistle (Cirsium), but the heads are very different in shape and structure. The spherical compound heads consist actually of numerous 1-flowered heads, each with an involucre of several spine-tipped phyllaries surrounded by abundant stiff hairs or setae around the base. Other species are cultivated and may also escape.
All species found in Echinops
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. March 29, 2017. http://michiganflora.net/genus.aspx?id=Echinops.