Missouri evening-primrose, Oenothera macrocarpa

Five inches! Missouri is the largest flowered evening-primrose I know of. Or not. It's also a beautiful example of variation. There are five distinct varieties from separate regions of our central plains. They are vary different, some with smaller flowers. So why varieties instead of species? Much the same story as with humans. They are regionally distinct, but where they do have contact, intermediates occur and make the boundaries between varieties very unclear. The species occurs in our gardens, where most of the intermediates also appear, and in AR, IL, KS, MO, NE, OK, TN, TX, and WY. I've seen them persisting along a country road in southern Ohio, and I'm sure such populations added by wildflower enthusiasts occur elsewhere. Cultivated, Lenawee Co MI, 6/6/14. Evening-primrose family, Onagraceae.