tes in ferns were higher (33 out of 58 samples) and showed specificity to Glomeromycota (Fig. SI). Ferns exclusively contained members of the order Glomerales, with the exception of one Ophioglossum (Diversisporales), one Psi/arum (Archaeosporales), one Tmetipteris (Archaeosporales), and three 1394 New P