hoary vervain, Verbena stricta

Hoary vervain was originally a plant of the great plains. It has now taken advantage of human transportation and clearing of land, and occurs in all states except AK, CA, FL, HI, LA, MD, ME, NH, OR, RI, SC, and VA, and in ON and QC. The flowers are about 1/3 inch across. Chippewa Co WI, 7/8/11.