Scanning electron microscopy was used to examine the variation in perispore characters within and between six currently recognized taxa of the genus Gymnocarpium Newm. in North America. Representative scanning electron micrographs are presented and depict the perispore features observed. Spores of those taxa studied here do not each possess a distinctive morphology providing practical species discrimination, rather they all exhibit similar patterns of variation. Spore size was also examined and shown to be correlated to ploidy level, permitting positive identification of the diploid taxon G. dryopteris ssp. disjunctum from the tetraploid G. dryopteris ssp. dryopteris.