Spotted Knapweed is in the Aster Family. It is a noxious, invasive weed with many thistle-like lavender flowers that persist after drying.
It flowers from June to October, and is found in open dry sites with poor, gravel, or sandy soil; fields, forest openings, grasslands, prairie, streambanks, disturbed areas, roadsides, railroads, rangelands, dunes, barrens, overgrazed pastures. This is primarily a weed of the northwestern states and southwestern Canada, but reported in every U.S. state except Alaska, Texas, Oklahoma, and Mississippi.
Photographed in Wurtsboro, New York, USA