Celandine poppy (Stylophorum diphyllum )
I may have some to trade in the spring.
They grow easily from seed (I hear), so you may want to try and trade for some seed and maybe wintersow them.
I've intended to collect seed b4, but one time I look at it, and there is a fuzzy green seed pod, and the next time I look, there is no sign of it.
What plants might you have to trade if I have extras and you are still interested?