Euphorbia esula

Stem is smooth, blueish - green and produces a milky sap when broken.  Plant can grow to 3.5' and can take over large fields, pastures and other open areas.  Displaces native plants.  Seeds explode out of seed pods traveling up to 15', have a high germination rate and persist for up to 7 years. This plant is prohibited in New York; it is illegal to purchase, sell, transport or propagate.