Five new species of corticolous pyrenocarpous lichens are described from tropical and subtropical forests in the Chaco and Misiones provinces in NE Argentina: Aspidothelium submuriforme with globose, grey ascomata and ascospores mostly 7-septate with 0–2 oblique longitudinal septa, 25–28×8–10 µm; Pyrenula inspersoleucotrypa, characterized by a thallus without pseudocyphellae, aggregated ascomata, an inspersed hamathecium, and ascospores of 17–20×6·5–8·0 µm with diamond-shaped lumina; Pyrenula punctoleucotrypa, which has a thallus with pseudocyphellae, aggregated ascomata in a conical pseudostroma, with fused ostioles, not inspersed hamathecium, and ascospores of 10–12×4–5 µm with rounded lumina; Strigula muriconidiata, containing immersed pycnidia with hyaline, densely muriform, ellipsoid conidia, 90–103×32–35 µm; Trypethelium globolucidum, forming sessile pseudostromata with black and whitish parts, an inspersed hamathecium, ascospores 13–19-septate, (65–)83–97×11·5–14·5 µm, lumina rounded to lentiform and containing lichexanthone.

The species described in or referred to the genus Melanophloea, traditionally referred to the Thelocarpaceae, are discussed. Detailed observations on two species, including the type species, show that they have not much more in common than their polysporous ascus. Melanophloea is reduced to the type species, M. pacifica. It shows a close resemblance to Aptrootia in the Trypetheliaceae, and it is therefore tentatively referred to this family. Melanophloea americana is shown to be close to Thelenella in the Thelenellaceae. The latter species and the related M. montana are newly combined into this genus as Thelenella americana and T. montana. Thelocarpon nigrum, which was recently compared to Melanophloea, is retained in Thelocarpon in the Thelocarpaceae. Polyspory is suggested to facilitate dispersion, especially when compared to parent taxa that produce large muriform ascospores. Based on the current classification, polyspory originated at least 57 times within the lichenized ascomycetes, a clear example of convergent evolution.

Strigula confusa Fryday, Coppins & Common is described from the western British Isles, where it grows over bryophytes on mildly basic rocks. The concept of the genus Thelenella is expanded to include Chromatochlamys and the following new combinations are made: Thelenella larbalestieri (A. L. Sm.) Coppins & Fryday, Thelenella muscorum var. octospora (Nyl.) Coppins & Fryday, Thelenella vezdae (H. Mayrhofer & Poelt) Coppins & Fryday. Thelenella sordidula (Th. Fr.) H. Mayrhofer is reported for the first time from Europe (Svalbard).