We conducted a survey on the mycorrhizal status of neotropical ferns, focusing on
previously neglected taxa. These include the filmy ferns (Hymenophyllaceae), grammitid ferns
(Polypodiaceae), and the genus Elaphoglossum (Dryopteridaceae). Samples were collected at
different sites in southern Ecuador, Prov. Loja, Morona-Santiago, and Zamora-Chinchipe. Among
the 85 investigated species (101 samples, 10 families), 19 were associated with arbuscular
mycorrhizal fungi (AMF) and 36 were infected by dark septate endophytes (DSE), which are
identified as ascomycetes and here considered as a kind of mycorrhiza similar to the ericoid type.
The roots of 30 species (including all non-grammitid Polypodiaceae and half of the Elaphoglossum
species) were free of evident fungal infection. AMF were frequent in terrestrial species (29.10% of
species, or 48.49% of infected terrestrial samples). DSE prevailed in epiphytic species (58.62% of
species, or 96.15% of infected epiphytic samples) and were also common in terrestrial samples of
predominantly epiphytic species.