I wrote a few days ago about a pink flower that had appeared out of nowhere and said my guess was some sort of mimulus. Well, it is close by another plant which often appears but I’ve never planted and I’m even more sure this is a type of mimulus. Having said that, the scientific name may well have changed.
This appears to be the Yellow Monkey Flower Erythranthe guttata formerly known as Mimulus guttatus.
There are many cultivars originating from the original North American wildflower. Personally, I don’t care for it. The fleshy stems (which break very easily) remind me of begonias, which I am also not a great fan of.