Heracleum mantegazzianum Sommier & Levier (Apiaceae) Giant Hogweed is an invasive plant that disperses through seeds and by spreading roots. When the sap contacts skin and reacts with light, large, liquid-filled blisters result. It can be found most commonly along roadways, and it is very likely to be found in other similar sites in Massachusetts.
The Massachusetts Department of Agricultural Resources (MDAR) has a website that collects information on invasive species. The MDAR Hogweed report form can be found here.