Caltha leptosepala is quite common on wet sights across western North America. The lumpers and splitters do not agree on the number of subspecies (I guess that's normal :rolleyes:).
I have noticed that I see two forms, when I come across them in the Sierras. One form displays it's narrow sepaled flowers on longer stems 12"-18" (30-45cm) the other form has some what wider sepals displayed at 6"-8"(15-20cm) in height. In all other respects they appear to be equal.
I like the shorter form better.
The taller form
The shorter form