Rhytidhysteron, Spegazzini, 1881

Cobos-Villagrán, Aurora, Raymundo, Tania, Calvillo-Medina, Rosa Paulina & Valenzuela, Ricardo, 2021, Rhytidhysteron mexicanum sp. nov. (Dothideomycetes, Ascomycota) from the Sierra of Guadalupe, Trans Mexican Volcanic Belt, Phytotaxa 479 (3), pp. 275-286 : 283

Key to species of Rhytidhysteron from Mexico

1. Hysterothecia shell-shaped, globosose or subglobose, straight.................................................................................. R. thailandicum

1. Hysterothecia navicular, elongated, flexuous.....................................................................................................................................2

2. Exciple of hysterothecia smooth ................................................................................................................................... R. neorufulum

2. Exciple of hysterothecia striate ..........................................................................................................................................................3

3. Ascospores with only one, central septum ............................................................................................................... R. neohysterinum

3. Ascospores three-septate ....................................................................................................................................................................4

4. Hysterothecia with epithecium orange to red, releases magenta pigments in 10% KOH, ascospores 22–30 × 8–9 µm ..................... ............................................................................................................................................................................................. R. rufulum

4. Hysterothecia with epithecium yellowish green to pistachio green, releases amber pigments in 10% KOH, ascospores 34–44 × 10–15 µm....................................................................................................................................................................... R. mexicanum