Ragwort - not a very impressive name, and not at all certain why it's called ragwort; maybe the sort of torn/worn margins of the upper leaves. Senecio has 1000-1500 species ranging from herbs like this to vines, shrubs, and even trees. The ragwort shown is Senecio plattensis and the reason the Phactors have this species in their gardens is that it grew in a sand prairie-oak savanna that surrounded our Mississippi River cabin. When we sold the place a piece of the ragwort was among a few plant souvenirs. This ragwort grows near the outer edge of the shady area under the crown of a huge burr oak, on the south side, so it's a area of dry light shade, a tough place for any plant. But the ragwort does pretty well there even though our soil is far, far from sandy. It does spread, but not rapidly, maybe due to the much heavier soil, it's very hardy, and it's a quite cheerful late spring, early summer flowerer. Lastly, it's a native plant. What's not to like?