by their rather unique coloration and spots.. ???

ken

Here is a link that might be useful: link

It's quite likely that they are forsythia. It roots easily from branches that touch the ground, and then those grow into new shrubs. Fast growing, too, the new plants can often reach adult size in 2-3 growing seasons.

An untended forsythia allowed to grow will soon become a large colony of them, not unlike the way strawberry plants spread via runners.

Thank you denninmi. That really helps. I will cut out everything that is known to be non-forsythia and trim everything else as if it is forsythia. Next Spring, it will be fairly easy to see which is which, I expect.

Ken, the link you sent showed all flowering forsythias. If they were flowering, I would be okay, I think. The thing is that there does not seem to be any unique-ess to the leaves which is why I posted this and why I believe denninmi may be correct.