Prairie sundrops are indeed a plant of open land. They get a foot or two tall and bloom in early summer before taller plants mature. They've become popular in gardens, and their unassisted range in obscure northward and to the east. This image is from along a farm field not far from other prairie plants like blazingstar, prairie dock and big bluestem, and across the road from a garden that included it. Hard to know if this population was an opportunity for the plants or the gardener. Prairie sundrops grow in AL, AR, CT, IA, IL, IN, KY, LA, MA, ME, MI, MO, MS, NH, NJ, NY, OH, PA, TX, VA, VT, WI, WV, ON, and QC. Lenawee Co MI, 6/21/11. Willow-herb family, Onagraceae.