Small beggar's-ticks does indeed seem to be the smallest of our species of Bidens. Although descriptions say it can get six feet tall, I've never seen them much above knee height. In any case, the burs will get you just like the other species. These flower heads are typically about a quarter inch across, but can be only an eighth. Small beggar's-ticks grows in damp ground in AL, AR, CT, DE, FL, GA, IA, IL, IN, KY, LA, MA, MD, ME, MI, MN, MO, MS, NC, NH, NJ, NY, OH, OK, PA, RI, SC, TN, TX, VA, VT, WI, WV, NB, NS, ON, and QC. Lenawee Co MI, 9/2/11. Aster family, Asteraceae.