Cladonia krogiana Løfall & Timdal

A lichen with large primary squamules quite recently circumscribed from Norway (Løfall & Timdal 2002). The dominant primary thallus is composed of conspicuous squamules without a pronounced grey or yellow colour and may resemble C. polycarpoides or C. cervicornis s. lat. It is reliably identified based on the unique content of the xanthon vinetorin and a depside of barbatic acid. Although the substances usually have characteristic spot reactions (C or KC+ orange or red), the lichen itself has negative spot reactions. Cladonia krogiana is for now only known without podetia and immature apothecia were rarely found in the Norwegian material directly on the squamules (Løfall & Timdal 2002).

Cladonia krogiana is probably widely distributed in the arctic-boreal-temperate zone of the northern hemisphere but is obviously very rare with specific substrate and microhabitat requirements. Its ecology varies within its known distribution area. In Norway and Canada, it has been recorded on open exposed rock outcrops in an ecotone of forest and water, on banks of larger rivers and lakes, and at places probably inundated during spring (Løfall & Timdal 2002, Clayden et al. 2021). In Greenland, the species has been documented on snow patches on soil with pH 5–6 (Bültmann & Lünterbusch 2008). In the Czech Republic, it is only known from humus on a low ultrabasic rock outcrop in an open pine forest at the Ranský Babylon hill in the Žďárské vrchy hills (Palice et al. 2018). Similarly, the only known occurrence on an acidic rock outcrop at lower elevation in the Alps is not directly associated with water (Dietrich et al. 2020).

Literature: Løfall B. P. & Timdal E. (2002): Cladonia krogiana, a new xanthone-containing species from Norway. – Lichenologist 34: 277–281. Bültmann H. & Lünterbusch C. H. (2008): The Cladonia cariosa group in Greenland. – Abhandlungen aus dem Westfälischen Museum für Naturkunde 70: 305–312. Palice Z., Malíček J., Peksa O. & Vondrák J. (2018): New remarkable records and range extensions in the central European lichen biota. – Herzogia 31: 518–534. Stenroos S., Pino-Bodas R., Hyvönen J., Lumbsch H. T. & Ahti T. (2019): Phylogeny of the family Cladoniaceae (Lecanoromycetes, Ascomycota) based on sequences of multiple loci. – Cladistics 35: 351–384. Dietrich M., Keller C., Mermilliod J.-C. & Vust M. (2020): Beiträge zur lichenologischen Erforschung der Schweiz – Folge 2. – Meylania 66: 4–18. Clayden S. R., Ahti T., Pino-Bodas R., Pitcher M., Løfall B. P., McCarthy J. W. & McMullin R. T. (2021): First documented occurrences of Cladonia krogiana and C. rangiformis in North America. – Opuscula Philolichenum 20: 25–36.

Ascomycota → Lecanoromycetes → Lecanorales → Cladoniaceae → Cladonia