Leafy Spurge
Leafy spurge, wolf's milk leafy spurge, or wolf's milk is a species of spurge native to Europe and Asia, and introduced in North America, where it is an invasive species.
Leafy spurge grows in a variety of different climate environments. It displaces native vegetation in prairie habitats and fields through shading and by usurping available water and nutrients and through plant toxins that prevent the growth of other plants underneath it.
It is an aggressive invader and, once present, can completely overtake large areas of open land. Leafy spurge quickly colonizes in areas with bare soil, especially those caused by human disturbance where native species are removed.
One method of control suggested is to limit the amount of bare soil from these disturbances.
It is toxic as well.