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 Phytologist (2015) 205: 1394-1398 wmv.new