Trollius albiflorus (syn. Trollius laxus ssp. albiflorus) is a common plant of wet alpine meadows, blooming shortly after the snow recedes. I find that the white ticking at the leaf-section junctions makes the plant readily identifiable amongst the other meadow foliage, after the bloom season.
http://www.efloras.org/florataxon.aspx?
Odd that e-Flora of North America claims it occurs in more-or-less acidic substrates, while it is also a common plant here in the front ranges of the northern Rockies, where extremely thick sections of limestone and dolomite form vast outcrop exposures and alkaline substrates.
http://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Trollius%20albiflorus...
http://plants.usda.gov/java/nameSearch?keywordquery=trollius+albiflorus&...
http://www.swcoloradowildflowers.com/white%20enlarged%20photo%20pages/tr...