Wild parsnip is a plant indigenous to Europe, introduced to North America, and now a common feature of many of our wild meadows and fields. While it is considered an aggressive invasive in many places, it is also a host plant for the Black Swallowtail butterfly who lays her eggs on it. This year I found countless Black Swallowtail caterpillars on wild parsnip. It has a darker side, however, as anyone who has tried to cut it down will know. If you break the stems and get the sap on your bare skin, and are then hit by sunlight, you will get a nasty rash that will blister and burn and leave its mark for some time. This is called photodermatitis. Just touching the plants doesn't usually cause any problems. I've handled them for years and had no issues, but I've been careful not to break leaves or stems either. They produce big umbels of yellow flowers which butterflies and other pollinators love, and then these seeds late in the summer.