Autecology of pteridophytes may be refined by defining the plant community and habitat, and phytogeographic occurrence, of the species studied. Work with Blechnum spicant in the Pacific Northwest, and with Lorinserea areolata in the Southeastern U.S.A. has uncovered autecological differences for these species across habitats differing in overstory and hydrology. Natural history observations are necessary to suggest the most appropriate hypotheses to investigate objectively. A modification of Daubenmire's Canopy-Coverage method provides a grid across which many factors may be recorded or tested in repeatable objective manner. Such an analysis was used to test the association between L. areolata life-history classes and hummocks in hardwood swamps. Contingency tables were used to disprove the null hypothesis that L. areolata was distributed randomly with regard to hummocks. Hummocks were thus ‘safe sites’ for the completion of the life-cycle of L. areolata, and additional considerations of safe sites for Lygodium japonicum and Dryopteris ludoviciana are introduced. Analysis of biomass and coverage of Onoclea sensibilis where it is very abundant suggests that it is highly susceptible to competition where it shares plots with L. areolata. The concept of the optimum habitat with regard to abundance of the taxon, frequency of the habitat-type, successful reproduction, and susceptibility to competition between similar life forms is discussed.