Cladonia cervicornis (Ach.) Flot. s.str.

A lichen forming large, elongate, partly ascending basal squamules, while podetia are often absent. In dry conditions the squamules are frequently contorted and rolled upwards, exposing the white lower surface, which often has a pinkish to purplish tinge. Older squamules, especially towards the base, darken to purplish to bluish grey, sometimes even brown. Morphologically, this taxon overlaps with the very similar and closely related C. verticillata, which is characterized by smaller, less deeply incised squamules lacking a distinct purplish coloration. In general, however, C. verticillata is distinguished by taller podetia, usually with several tiers, whereas C. cervicornis typically has only a single tier, or additional tiers that are poorly developed. Another very similar species is the recently described C. teuvoana, which differs in having a less well-developed primary thallus with a white underside and narrower scyphi that widen abruptly.

Cladonia cervicornis is a suboceanic lichen occurring scattered from lowlands to mountains in Central Europe. In the Czech Republic, however, it shows a clear preference for low to middle elevations. It often occurs in river valleys and sandstone “rock cities”, where it is a typical species of relict pine forests, heathlands and sandy sites with low competition from vascular plants. It grows on nutrient-poor, usually acidic soils. At higher elevations the species is noticeably rarer; there it occurs, for example, on sun-exposed rock outcrops and boulders covered by a thin layer of soil, on rocky ridges, screes, and solitary boulders in pastures.

Literature: Van Herk C. M. & Aptroot A. (2003): A new status for the Western European taxa of the Cladonia cervicornis group. – Bibliotheca Lichenologica 86: 193–203. Pino-Bodas R., Herrero A., Aptroot A., Søchting U., McMullin R. T. & Burgaz A. R. (2024): Phylogenetic study of the Cladonia cervicornis group (Cladoniaceae, Lecanorales) discloses a new species, Cladonia teuvoana. – The Lichenologist 56: 237–258.

Ascomycota → Lecanoromycetes → Lecanorales → Cladoniaceae → Cladonia