Spore studies in the genus Gymnocarpium

PRYER, K. M., and D. M. BRITTON. 1983. Spore studies in the genus Gymnocarpiurn. Can. J. Bot. 61: 377-388. Scanning electron microscopy was used to examine the variation in perispore characters within and between six currently recognized taxa of the genus Gyrnnocarpiurn 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. disjuncturn from the tetraploid G . dryopteris ssp. dryopteris.