Yesterday's incredibly bright sun did indeed coax open the flowers, along with more green leaves. As you can see, it was one seriously sunny day - the tree shadow is what really allows us to enjoy the flowers in this image. So, any new thoughts on what this might be? I'll keep searching!
Here's a thought: perhaps this is another type of ranunculus? I just learned that one of my favorite flowers, the columbine, is also a part of the ranunculus family... who'd have guessed?
I spent yesterday afternoon with the landlady and learned many new things about the surrounding trees and plants on the farm, as well as their history. There is so much to share!