Asplenium samples used in this study with voucher information, collecting locality, substrate specificity, ploidy level and GenBank accession numbers.

aUnmounted specimens in the Molecular Lab Herbarium.bAvi288 and Avi289 were included in the Asplenium metagenome for the discovery, typing and quantitative evaluation of DArT markers, but were excluded from subsequent analyses due to substrate ambiguity.cAs expected for an allopolyploid hybrid, the nuclear locus pgiC exhibits heterozygosity at the DNA sequence level and was thus not submitted to GenBank.