Stickyweed, aka Cleaver or Sweetheart, is a highly weedy invasive in the PNW. It has vining tendencies and burs which allow it to spread quickly and choke out native plants. They are easily identified by their small sticky hairs covering stems and leaves which allow them to stick to just about anything they touch. 

To remove Stickyweed, follow them to the base and try to pull up roots. All pieces must be bagged and disposed of to prevent spread.