Cladonia glacialis


Cladonia glacialis is a rare species of fruticose lichen in the family Cladoniaceae. It is only known from a single locality by a glacier in central Iceland.

Taxonomy

It was described as a new species in 2009 by Hördur Kristinsson and Teuvo Ahti. Kristinsson collected the type specimen in 1979 from Arnarfellsmúlar at an elevation of. This type locality is on the southeast side of Múlajökull, which is an outlet glacier of the Hofsjökull ice cap. At the time of its original publication, Cladonia glacialis was only known to occur at the type locality.
The authors suggest that the species belongs to the "supergroup" Cladonia, and that it may be closely related to Cladonia phyllophora.

Description

Cladonia glacialis is a lichen species characterised by its slender growth habit. The primary are inconspicuous but persistent, measuring 2–3 mm long and 1–2 mm wide. These squamules are flat, minimally divided, and display a distinctive colouration with glaucous grey on the upper surface and pure white underneath, featuring melanotic bases.
The podetia range in colour from deep grey to pale brown with a finish. They typically grow 3–4 cm tall and 0.8–1.5 mm thick, appearing slender with minimal branching. These structures can be either or narrowly, with the cups measuring 0.5–2 mm in width. The melanotic darkening also appears inside the bases of the podetia.
The surface texture of C. glacialis is rough, with continuous but -knobby cortex throughout. At the base, the cortex occasionally bursts into white spots. The scyphi develop granular soredia in patches and often proliferate from their margins to form 3–7 subulate branchlets. Sometimes the podetia branch dichotomously without forming cups. The podetial squamules are scarce and small.
Apothecia have not been observed on this species but are presumed to be brown if present. The conidiomata appear terminally at podetial tips or on scyphus margins. They are broadly and .
Chemically, C. glacialis tests negative with potassium hydroxide colution and positive red with p-phenylenediamine. It contains fumarprotocetraric acid with traces of protocetraric and fumarprotocetraric acids, plus a minor unidentified compound detectable through thin-layer chromatography.