1

Thallus on soil or bryophytes

P. australis

1:

Thallus on rock

2

2

Perithecia lacking an involucrellum

P. dermatodes

2:

Perithecia with an involucrellum

3

3

Spores 30–55 µm long, remaining colourless; on dry limestone

P. cupularis

3:

Spores 52–81 µm long, becoming brown; on aquatic rocks

P. cruenta

Modified from McCarthy (2001e)