Philadelphus coronarius is not native to Wisconsin but it is widely planted. It also does not appear to escape from cultivation. I include it here only because it can persist long after cultivation and after the passage of many years it may appear to be a wild plant.

Mock orange may be recognized by the simple opposite leaves with very distant, small teeth, and by the presence of buds hidden under the base of the petiole. As a consequence the plant will appear to have no buds when leaves are still on the twigs. After the leaves fall, the bud will be within the leaf scar and not above it as in most of our woody species.