Thanks! It seems to have been there for years. It's established. We have 1.5 acres of slope, and we are in a dry climate, and it gets some water where it is planted. Your link said it gets invasive near streams or riverbeds. I only see one large plant on our slope and it sure is pretty! I wouldn't mind having other colors near it. Suzi

Chelidonium majus Here is a link that might be useful: Greater celandine

I have found that the flowers are typically more of a rose pink than the brilliant red shown in many photos (a bit of photo enhancement perhaps?). They are biennial, blooming the second year, then declining--sometimes after first bloom, you can stretch them for one or two more years. They are relatively easy from seed.

Yes, I'm also not happy about how Houzz changed the forum list around. Trying to find your forum, is like trying to find a needle in a haystack now. I have found that if you google the forum you want, you can get there faster, like if you want the Butterfly Forum, you can google gardenweb butterfly forum. Your plant looks like something in the Aster family, either Rudbeckia, or Helianthus.