Abstract: Athyrium filix-femina  var. asplenioides  is one of more than six regional taxa in a diverse species complex, A. filix-femina  sensu lato, that occurs world-wide.  Many questions about the organization of genetic variability of this complex are unanswered, especially the amount of genetic divergence among populations in relationship to geographic proximity.  This study was conducted to determine the amount of genetic divergence for isozyme loci in asplenioides  of the Southern Appalachians among populations at differing elevations at widely differing latitudes in Virginia.  Thirteen populations were evaluated for allele-frequency divergence at scales ranging from subpopulations to geographic regions separated by hundreds of kilometers.  Highly uniform allele frequencies were observed across all sample locations, resulting in very low Fst values for each allele (mean Fst =0.068). Geographic distance and elevation have slight, if any, effects on population structure, with the hierarchical Fst for region to total being -0.011, and the Fst for elevation to total being 0.009.  Rogers' similarities were calculated for each pair of populations and used to form a UPGMA dendrogram that showed a small amount of organization by locality and elevation.  It appears that gene flow occurs at substantial rates among asplenioides  populations across relatively large distances, and that there is some allele sharing of Southern Appalachain populations of A. filix-femina var. asplenioides with A. filix-femina  var. angustum.