Should I pull it out? It didn't look like a weed so I kept it. The leaves almost looks like the phlox I have. ( photo / image / picture from Tina's Garden ) ( photo / image / picture from Tina's Garden )
Looks like Buddlea Davidii to me too,and BTW it may not necessarily be one that you already have.I have several volunteers in my garden that came from nextdoor quite a few years ago now
It is lovely. Silly me, I would likely move the irises and keep the shrub where it is, unless it causes trouble there.
I also think I would move the Iris instead. They don't have a large root system and recover very well from being moved. With a Buddlea that size, the roots are already going to be spreading out and losing too many roots can endanger the plant.
Actually it is right in the front yard by my driveway, so not sure if the shrub will look good there.