Let me first say I started growing poppies last year and I adore them. I winter-sew seeds each year with moderate sucess. They are tough to establish!
My problem is the plant pictured below has invaded a new bed I prepared last year. I intended for it to be a bearded Iris border, but instead it was full of this plant. I didn't let any of it bloom; I took it for a weed and cut back what I could. but someone on the I. D. forum says it's Celandine (Chelidonium majus). If so, than Celandine forms a hairy, perennial, basal rosette that is looking healthy despite the freezing temps! It also seems to form aggressive underground rhizomes. I found no mention of these characteristics on the web anywhere (just pictures of the mature plant). Since Celandine is a poppy, I thought it could be IDed positively here. Thanks for your help!
Because the conditions for it to grow must be ideal.
It is a pioneer plant that naturally occurs in light woods along rivers, and in walls. It likes nitrogen-rich alkaline soil in shadowy places.
If you don't let them self seed, they eventually will disappear.
It is easy to pull out. Personally I find it has charms in a natural garden.