Vesicular-Arbuscular Mycorrhizae of Southern Ontario Ferns and Fern-Allies

Thirty-nine species and varieties of common Pteridophytes of southern Ontario were surveyed for the presence of VAM. The sporophytes of the three Equisetum spp. and the two Lycopodium spp. examined were usually non-VA mycorrhizal. The two species of Botrychium were extensively VA mycorrhizal, while the Filicales were in general moderately colonized, though plants from isolated rock outcroppings and crevices were often non-VA mycorrhizal. These observations are discussed in light of Baylis' theory of root morphology and mycotrophism. In addition, various root-inhabiting fungi which could be confused with VAM are illustrated.