Collected 23rd April 2026, Norfolk, England
Swarms of white apothecia (0.1-0.2mm diameter) on surface of blackened Pteridium aquilinum (Bracken) stems, just below ground level.
Apothecia with short stalks
Superficial on the substrate surface (ie nor emerging from within the stem).
All white - no differentiation in colour between the internal hymenial disc, rim or external (ectal) surface.
No marginal hairs evident
Ascospores (5.7-) 6.4 (-9.3) x (1.0-) 1.5 (-1.8) n=10 with guttules at each end.
In the UK, collections like this appear to be recorded as Micropodia pteridina, supported by the entry in Ellis & Ellis Microfungus on Land Plants (2nd Ed. 1997).
However, Zotto Baral (Micropodia pteridina, a misinterpreted fern-inhabiting discomycete with unclear relationship within the Helotiales, Baral H.-O., 2023, ascomycete.org 15 (1): 1-8) points out there are several confusion species:
Psilachnum sp. (chrysostigma agg.)
Fuscolachnum pteridis (sessile and with marginal hairs so ruled out in this case?)
Mycroscypha arenula (but only on leaves, not stems?)
Mollisia sp.
According to Zotto's paper, these species can be differentiated with regard to exicipular structure, presence/absence of marginal hairs and apothecial stipe and apothecial development.
I have the opportinity to ITS barcode but with no publicly available reference sequences for M. pteridina, is there any benefit?
Tony Moverley
Norfolk Fungus Study Group