Lecidea praenubila Nyl.

A lichen with a dark, chestnut brown, glossy areolate thallus, composed of lightly bordered squamules on a dark prothallus. It resembles species of the L. atrobrunnea complex, as well as remotely related lichens, such as Immersaria athroocarpa. Lecidea paupercula is sometimes distinguished from L. praenubila (Hertel 1995, Nimis et al. 2018), differing only in its more intensely pigmented hypothecium. However, most of the recent sources join the two entities together. Lecidea praenubila differs from the most similar, broadly delimited taxon L. atrobrunnea in its larger and broader ascospores. Chemistry can also be used as an auxiliary criterion, in particular the presence of stictic acid, which, however, may less frequently be found also in the L. atrobrunnea complex.

In Europe, it is a less common arctic-alpine species with a centre of occurrence in the mountain regions and northern Fennoscandia. In the Alps, it is apparently rare and in Austria, for example, the occurrence of L. praenubila s. str. has not been confirmed at all (Nimis et al. 2018). The identity of two historically published records from the Czech Republic is unclear. However, it is almost certain that findings at lower elevations, i.e. on basalts near Most (Servít & Klement 1933, as L. aeneola), are confusions. The only reliable record comes from the Velká kotlina corrie in the Hrubý Jeseník Mts (Suza 1928, as L. paupercula), where, however, the lichen has not been confirmed during recent surveys.

Literature: Suza J. (1928): Zajímavé nálezy lišejníků v Československu. – Časopis Moravské zemského musea 25: 283–287. Servít M. & Klement O. (1933): Flechten aus der Čechoslovakei. III. Nordwestböhmen. – Věstník Královské české společnosti nauk 1932/13: 1–37. Hertel H. (1995): Schlüssel für die Arten der Flechtenfamilie Lecideaceae in Europa. – Bibliotheca Lichenologica 58: 137–180. Hertel H. & Leuckert C. (2008): Lecidea atrobrunnea in Europe and adjacent parts of Asia and Africa. – Sauteria 15: 215–238. Nimis P. L., Hafellner J., Roux C., Clerc P., Mayrhofer H., Martellos S. & Bilovitz P. O. (2018): The lichens of the Alps – an annotated checklist. – Mycokeys 31: 1–634.

Ascomycota → Lecanoromycetes → Lecanorales → Lecideaceae → Lecidea