Pronectria pertusariicola
Anamorph: not known.
Teleomorph: ascomata perithecia, immersed in the host thallus, scattered or in clusters but not stromatic, in surface view as minute pinkish orange dots; 140-170 µm diam., subglobose, not or hardly papillate, not setose, the wall and content orange, not reacting in KOH. Ascomatal wall composed of an outer layer of thick-walled angular to rounded cells and an inner layer of thin-walled ± elongate cells. Asci cylindric-clavate, 40-65 x 6.5-8 µm, thin-walled, rather short-stalked, the apex rounded, without a distinct apical ring, 8-spored. Ascospores arranged obliquely uniseriately or partially biseriately, 7.4-8.6 x 4.3-4.8 (-5.4) µm, ellipsoidal to cylindric-ellipsoidal, slightly constricted at the median septum, fairly thick-walled when completely mature, smooth or with a minute, rather remote spinose ornamentation, pale yellowish when mature, without a perispore or gelatinous appendages.
On thalli and thalline warts of Pertusaria pertusa, apparently biotrophic with little or no damage to the host. Less commonly reported on other Pertusaria species (including P. hymenea and P. leioplaca). Records on Lepra may refer to a distinct species.
SW England, Wales, N. England and upland Scotland.