Large St. John's-wort? We generally think of St. John's-worts as relatively showy plants, with lots of flowers a half inch or more across. Maybe that preconception explains this name. These are at most a quarter inch across, relatively scattered on small plants. Although there are lots of other even smaller flowered St. John's-worts. So maybe this was a big fish in the small pond? Large St. John's wort grows in open, usually damp areas in CO, CT, DE, IA, ID, IL, IN, KS, MA, ME, MI, MN, MO, MT, ND, NE, NH, NJ(E), NY, OH, OK, OR, PA(T), RI, SD, VT, WA(S), WI, AB, BC, MB, NB, NS, ON, PE, QC, and SK. Kitty Todd Preserve, Lucas Co OH, 9/2/13.