“…Looking at cryptogams the only one meeting these criteria as a model to date, is the hornwort Anthoceros agrestis (Szövényi et al, ). Ceratopteris thalictroides (Hickok et al, ; Renzaglia & Warne, ), the moss Physcomitrella patens (Lang et al, ) and the liverwort Marchantia polymorpha (Alam & Pandey, ; Bowman et al, ; Ishizaki et al, ), not to mention Arabidopsis, are all symbiont‐free. Though these absences are almost certainly secondary losses, recent in Marchantia and more ancient in Ceratopteris and Physcomitrella , they are far from ideal for studying the function of signalling network pathways that were present from the dawn of terrestrialization (Wang et al, ).…”