I'm trying to identify this tiny, but beautiful, weed that popped up overnight. Though I think I've seen it other places, I don't know what it is. It's upright, leaves are serrated and opposite. The flower is barely 1/4" with a deep yellow throat surrounded by white that becomes pale yellow. Sorry I can't be more 'scientific' in my description. It's a dainty beauty, and I'd love to know what it is. Thanks for any help.
