Abstract
This study analyzes the range-wide genetic diversity and population structure of American hart’s-tongue fern (Asplenium scolopendrium var. americanum, AHTF), a rare fern species in the eastern United States. AHTF populations from New York, Michigan, Alabama, Tennessee, and Canada are examined using combined simple-sequence repeat and inter-simple sequence repeat markers. Genetic data provide insights on levels of genetic diversity, population structure, genetic differentiation, gene flow, total allele frequency, number of rare alleles, linkage disequilibrium and mating system. Overall, three main genetic clusters were identified, which are represented by: 1) populations from NY; 2) all three populations from Canada and the rest of the populations from the U.S.; and 3) the commercially available hart’s-tongue fern. Genetic data is utilized to designate Evolutionary Conservation Units, Management Units and Relevant Genetic Units, particularly for the U.S. populations. This study recommends seven populations as priority for conservation and management in the U.S.