This is the other yellow-flowered winter aconite which is sometimes, rarely, seen in local gardens. It blooms much later than the usual winter aconite, Eranthis hyemalis, and in my experience is much trickier to grow. I'm getting the impression that it needs dry summer conditions. It's also a smaller plant overall.
By the time it finally blooms there is a lot else going on in the garden, so it's tempting to nominate this one for the collector's garden. I'll take a few, thank you.