This is growing wild in the prairie at our local Audubon nature center and also, in our neighbor's yard, by accident. Neighbor doesn't know what it is and extensive search of white WI wildflowers led me to Cow Parsnip. BUT...look at the leaves: they are more heart-shaped than maple-leaved. Also, the flower head in the pic has started to go to seed but in full bloom, was very sturdy with branching white bracts. Stem has a purplish cast and height is 10' for sure. Can't wait for some help on this puzzle.

Found this today on the seed rack at our local Audubon Nature Center. The volunteer who steered me in this direction mentioned that there may be more than one genus for any plant type: when we viewed a speciman together, the leaves were not at all like these. However, the flower bracts match. Check out the photo on the packet.

I don't understand what is meant by more than one genus for any plant type, but here's a picture of the plant on your seed package from the NGA database:

Yes, it is Pale Indian Plantain (Arnoglossum atriplicifolium) . Cacalia atriplicifolia, as listed on the seed packet, is an older scientific name for this plant.

The leaves directly below the inflorescence, which are the only ones that can be seen on the seed packet picture, are quite different in shape compared to the leaves that are lower down on the plant. That's why the leaves from the seed packet picture don't seem to match the leaves from your pictures.