It sounds like you're talking about what we call "Autumn Olive" not sure what its really called, but your description sounds like the same thing. This stuff is worse than kudzu because it gets pretty "woody" really fast. Small to medium bushes, I just hit with roundup and let em go. The really big ones, I hit with round up, and then come in and do as carl1191 suggested. Good luck, and dont let up. We've been at it for about 10 years and we're about to gain on it.