Japanese honeysuckle (Lonicera japonica) is an invasive vine we used to have in our yard, one we bought (highly recommended!) from our local plant nursery many years ago.
True, it was pretty, grew without much attention, and had a beautful fragrance to boot. So I was a bit sad about it, but yanked it out anyway. Any momentary pleasure we got from this plant was negated by the damage it could do. I never took a photo of it, but they can still be seen at almost any garden center. I'm sure there will be plenty there—unfortunately.
I found the vine in the photo growing in one of our flower beds. It must have been there at least a year, but since I think this is the first year it flowered, I guess I just didn't see it before. How did it get there? I assume from berries dropped by birds or the seeds in the bird poop. At least it was easy to pull out.
Fortunately, our native honeysuckle vines are real beauties—more beautiful than the Japanese variety, though, sadly, there is no fragrance.
This black swallowwort (Vincetoxicum nigrum) was definitely NOT planted in my yard on purpose. I don't think I would have even recognized it for what it was if it weren't for the fact that we had recently attended one of our HGCNY garden tours where the host pointed it out on his property.
I don't know how it came to be on my property—it probably hitched a ride on a plant I purchased, or maybe it just blew in as a seed.
Pale swallowwort (V. rossicum) among my ferns
The tragedy of swallowwort is that it's similar enough to native milkweed to trick monarchs into laying their eggs on it, but it's not chemically similar enough to support the caterpillars. They die.
It also crowds out native milkweed (and everything else in its path). A really tragedy all around. It's an especially dire problem in our local state parks, crowding out the magnificent natives that belong there and support life.
This black swallowwort seedpod hints at its relationship to native milkweed.
(This photo was taken at Green Lakes State Park since my swallowwort wasn't allowed to live long enough to set seed!)
Vinca invading a local nature center
It's hard to believe but when we first moved in, I found some stray bits of vinca (also known as periwinkle)—both (Vinca minor) and (V. major)—in the back yard. I gathered up all the bits and replanted it so it would gradually fill the back yard. And for the usual reasons: the blue flowers were so pretty, and it was easy to grow.
I'm now paying for that decision, since I've been battling it ever since. I definitely have much less of it, but I still find it coming up here and there.
At least I didn't BUY the vinca, as I did the English ivy (Hedera helix). Even though it was a couple of decades ago, I still remember how pleased I was to find such a good deal on a whole flat of English ivy!
This is another plant I'm still trying to eradicate. For the most part, I'm winning, but a few stray bits remain.