When I first encountered this flower eight years ago, growing near the small red barn in Herrontown Woods, I didn't look very closely and thought it was mock orange. A few years ago, the town hired the Invasive Species Strike Team to treat some non-native species that are just starting to spread through local preserves. To my surprise, this small shrub, which they called jetbead, was one of their targets. The aim was to catch invasions early, so that a small problem wouldn't become a big problem later on.
Jetbead (Rhodotypos scandens) -- This NC State website also calls it "white Kerria", which fits, if you've ever seen Kerria.