What's False About it?

It's always fun for a person who follows seasonal changes to predict the finding of a particular flower near the beginning of its season, then to find it where expected.  Thus was the case a week ago Friday, February 27, when I pulled off the road just west of the Rock Creek Powerhouse in the Feather River Canyon and parked below a rocky outcropping that is usually covered with a thin layer of flowing water.  There they were, around 50 feet above the highway in a tricky place to climb, a nice patch of Waterfall Buttercup clinging to the granite wall.
I did a little Internet search to refresh my memory of the taxonomy and other details pertaining to this lovely plant.  I had a vague memory of some issue about its scientific name.  I found several websites that named it Ranunculus hystriculus.  I also found a site that called it Ranunculus hystricula, which is bad grammar. [FYI, I took two years of high school Latin and never regretted it.] Then I found a site that naed the plant Kumlienia hystricula.  The author attached to this latter name was A. Gray.  I assume that was the Asa Gray of Harvard in the 19th Century, and that seemed to indicate that Kumlienia was an older name.  Not in the mood to split hairs, although that seems to be what I am doing now, I switched my attention to the fact that a number of websites call this plant by the common name of Waterfall False Buttercup.  I'm wondering what is or was false about it.  If the proper scientific name is Ranunculus, which is the generic name of all the other buttercups I'm familiar with, it seems Waterfall Buttercup would be appropriate. 
So, in keeping with my love of etymology, I'll be on the lookout for other members of the buttercup family, Ranunculuaceae, and at an appropriate time will update my discussion of this family which includes a wide array of flowers that don't look at all like buttercups.  One of my favorites is the Crimson Columbine.