It germinates annually from seed, but quickly attaches itself to a host plant, where it gets its nourishment. It no longer needs roots, since it is living off of the host plant. It quickly wraps itself around everything and anything in its path. As the season progresses, the plant blooms and sets seeds for next year. Eradicate as much as you can, as you can.
Next spring use a pre-emergent herbicide to prevent new attacks next season.
When the plant attacks annuals, I recommend sacrificing the annuals to get rid of it, but in raspberries, you probably don t want to lose the plants, so clean them up as much as possible. Be on the lookout next season to catch any errant sprouts before they overtake the plants. The Arkansas Cooperative Extension Service offers its programs to all eligible persons regardless of race, color, national origin, religion, gender, age, disability, marital or veteran status, or any other legally protected status, and is an Equal Opportunity Employer. The mention of any commercial product in this web site does not imply its endorsement by the University of Arkansas Cooperative Extension Service over other products not named, nor does the omission imply that they are not satisfactory.