Didymosphaeria marchantiae

Hosts: Marchantia polymorpha, Targonia hypophylla

Update: The systematic position of this fungus has jumped significantly. In Aproot’s 1995 monograph of Didymosphaeria, D. marchantiae was synonomysed with Phaeodothis winteri on the basis of their similar teleomorphs. Molecular and morphological data now suggest a close relationship with the generalist fungus Phoma herbarum. Related Atradidymella muscivora, which is certainly congenic, has been synonymised with Phoma herbarum s.str. in the below paper.

Chen, Q., Jiang, J. R., Zhang, G. Z., Cai, L., & Crous, P. W. (2015). Resolving the Phoma enigma. Studies in mycology, 82, 137-217.

This species is scarcely recorded though is likely not uncommon on old receptacles and thalli of Marchantia polymorpha. Many years ago, I observed the anamorph growing on the edges of old gemma cups of M. polymorpha in a car park in perthshire in Scotland. It is likely one of a rather small suite of (known) generalist fungi capable of saprophytic behaviour on bryophytes and vascular plants.

Images adapted from those stored in FGBI taken by Paul Cannon https://fungi.myspecies.info/all-fungi/atradidymella. Used with permission.

Two perithecia (arrowed) on an old archegoniophore of Marchantia polymorpha subsp. ruderalis. Image Paul Cannon; adapted with permission from the FGBI website.
Asci and spores of the above specimen, mounted in water. Image Paul Cannon; adapted with permission from the FGBI website.
Pycnidia of the fungus on decaying archegoniophore. Image Paul Cannon; adapted with permission from the FGBI website.
Conidia in water. Image Paul Cannon; adapted with permission from the FGBI website.