I have heard for years about the evils of Frangula alnus. " when Frangula alnus invades and grows in these locations, its dense canopy prevents light from reaching the ground and therefore prevents other seedlings from growing. It tends to grow more densely and with larger individuals in lower topographical areas with moist, fertile soils, and is very problematic for land managers." https://en.wikipedia.org/wiki/Frangula_alnus One guy in NY said it overran his land and he wished he had got ahead of it when he moved in. I heard it was in the village but I didn't think I would have to worry about it. Then I saw the yard was full of it. Right now, the birds are dropping those purple droppings on cars and pavement I had seen for years without knowing what it was. Then I thought I didn't to worry about it on the woodlot 20 miles north where I have many oaks and chestnuts planted. You can see one in the pix. I had hoped it was Alternate-leaved Dogwood (Cornus alternifolia) but 3 experts tell me it is Frangula. That means there must be a source near by and birds are spreading it. I have not seen it anywhere else but it has to be there. The only hope now is control and that means spraying. Eventually, it will still win. So is it really buckthorn and if not what? Thoughts ? Recommendations?