SallyG: It doesn't look like Corydalis to me, unless this is what Corydalis does in the sun. I do have a lot of Corydalis from Critter from a few years back. I'll take a cutting and compare - thanks for the idea. Mine is in the shade, and is wispy, but it might be a completely different animal in the sun.
It's not Corydalis cheilanthifolia, but that other Corydalis came to me by unknown means. There are more in Plantfiles that I didn't know but would like to have.
It sure does look like we are in the right family. It seems to have those juicy stems.
SallyG: I do believe you are right. It looks so different from my Corydalis plants in the shade -- it is compact and busy in the sun -- but I took a cutting and compared the two, and you are spot on. I don't recall it blooming -- I'll see what it does next year. I'll be perfectly happy if Feverfew and Corydalis wander around my awful front hill. Thank you!