Paranectria oropensis (Ces.) D. Hawksw. & Piroz.

Non-lichenized lichenicolous Ascomycota

    Visible on thalli of parasited lichens as greyings initially and then as whitish felt from where emerge perithecia. Perithecia globose, 150-250 µm diam., scattered or in small clusters on hyphae "carpet", bright orange when fresh turning to yellow-orange, beige-orange, ostiole dark bright orange, typically surrounded by cottony-like hyphae, labile and visible only for a few days. Asci 8-spored, clavate, thick walls, 65-80 x 15-21 µm. Ascospores ellipsoid, apices pointed, up to 10 µm  long, muricate, 6-8 transversal walls  and 1-2 longitudinal walls, 25-32 x 11-14 µm (without pointed apices). Parasite, rather active and markedly necrotic when parasiting corticolous foliose, leprose or crustose lichens on barks. Presented here on Physconia grisea growing on a Tilia bark).