Buckthorn
Buckthorn is a plant with simple, alternate leaves. One semi-unique characteristic is the way the veination curves upward towards the tip of the leaf. Dogwood is the only other commonly found plant in the northeastern United States with this characteristic, but the two plants are easy to tell apart because if one slowly pulls apart the leaves of a dogwood there are thin white latex strings. In the buckthorn these latex strings are not present. The plant bears fruits which are dark blue berries. The name comes from the fact that there is a woody spine on the end of each twig.
Common buckthorn (Rhamnus cathartica) is considered an invasive species in many parts of the United States. It has recently been discovered to be a primary host of the soybean aphid Aphis glycines Matsumura, which is a growing problem for soybean farmers across the country. The aphids use this invasive buckthorn species as a host for the winter and then spread to nearby soybean field in the spring.
