Potentilla species. not sure of which one but maybe Potentilla recta. Rhonda

I visited the plant in question this morning, and while under assault by a massive swarm of mosquitoes took some side views of the flowers. It appears that the petals are longer so I'm going to call it R. macounii. Thank you all again, you're knowledge is inspirational.

Maybe a Silphium? They're native wildflowers you might see in a garden center in Illinois. Prarie Dock, Silphium terebinthinaceum, has big basal leaves. WW Here is a link that might be useful: Prarie Dock

They could grow in WI and I'd venture to guess that some enthusiastic gardeners there do grow them. The Asian species of meconopsis have a reputation for being difficult to grow. This is largely due to being rather finnicky about climate conditions, although many are monocarpic and simply just not long-lived plants. They are certainly sufficiently cold hardy - they grow amazing meconopsis in Alaska - but what they have difficulty tolerating is summer heat and accompanying dry conditions. They are best suited to areas with a maritime influence that prevents excessive summer heat and affords ample rainfall....like Alaska, areas of the PNW, western Canada and most of the UK. The blue Himalayan poppies are almost the holy grail of gardening and dedicated gardeners in all climates will attempt growing these just for the possibility of producing these ethereal, incredibly blue flowers. Some succeed, many more fail. Meconopsis cambrica or Welsh poppy is the single species of this genus native to Europe. It is far more tolerant of a variety of climatic situations and will grow pretty much anywhere in the US. An annual species, it reseeds very willingly, to the point of being a weedy pest in ideal situations.