Brookside Pearly Everlasting
The pearly-white "rays" of Pearly Everlasting (Anaphalis margaritaceae) are actually multi-tiered involucral bracts, the part which is usually green in the composite flowers of the typical Asteraceae. The actual florettes are in the yellow "eye".
Pearly Everlasting isn't common in Western Uintas, with the notable exception of Provo River valley, where it colonizes streambanks like this one.
8/29/08