Border Privet (Ligustrum obtusifolium)
Arriving in the United States in the 19th century, it quickly spread due to its use as hedging on private properties but it has made its way into the wild now. Deciduous shrubs that can be semi-evergreen, they will grow from 8-20 feet tall if unchecked (hence the desirability as a hedge). Its leaves can be oval to oblong shaped, up to 3 inches in length, with small fragrant white flowers occurring in clusters at the end of branches, and small black-blue berries spherical-oval in shape. Privet grows through the spread of seeds by such means as birds, but can also spread through the sprouting of roots.
The issue with Privet as an invasive is also why people use it for hedges: it forms dense thickets which will shade out native plants as well as make new sprouts unable to grow. It also secretes a fluid that acts to prevent native insects from feeding on the leaves. When still unestablished, small plants can be uprooted by hand, while larger shrubs should be cut back and treated with herbicide. Herbicide can also be applied to leaves and bark to hinder growth.