All of our perennial native violets bloom through most of the growing season. We don't notice a lot of those flowers because, like the knotweed, they are partly cleistogamous. Cleistogamous flower buds don't open. They are self fertilizing. With violets, they sometimes appear underground, generated from the creeping stems or corms. Smooth white violets grow in moist shady areas in AL, AR, CT, DE, GA, IA, ID, IL, IN, KY, MA, MD, ME, MI, MN, MO, MS, MT, NC, ND, NJ, NH, NJ, NM, NV, NY, OH, PA, RI, SC, SD, TN, UT, VA, VT, WA, WI, WV, WY, across Canada except for YT, and on SPM. Washtenaw CO MI, 4/5/12. Violet family, Violaceae.