Cladonia rangiferina (L.) Weber ex F. H. Wigg.

   Primary thallus reduced to granules that disappear quickly. Podetions in a dense tuft 4-12 cm high and 5-10 mm in diameter, with clearly visible trunks, very branched with branches forming an acute angle, the last tetrachotomes, very short and folded in a crook to orient themselves in the same direction, surface typically felted and velvety (under a magnifying glass!), never scaly (no cortex), typically pale grayish, slightly silvery in dry weather, grayish, slightly pale greenish in humid weather, often invaded by a purple (more rarely bluish) tint, more distinct at the tips. Apothecia rare, very small, at the tips of the podetions, brown. Pycnidia at the tips of the branches, colorless jelly. Photobiont: trebouxioid. C-, K+ pale dirty yellow, KC+/- brownish yellow, P+ red-orange. A subarctic and subalpine species that grows in large colonies on acidic, stony soils in boreal forests (in France, collections from lowlands or hills are questionable and probably belong to different taxa).

Note: The species is strictly speaking subarctic and belongs to the "reindeer lichen" group, along with Cladonia stellaris, a species with which it is often associated in the far north.

Note: There is a very similar species, Cladonia stygia, which is grayer and more boreal.

Note: This species is frequently confused with Cladonia portentosa, Cladonia arbuscula, and Cladonia ciliata unless the precaution is taken to examine the surface of the pods with a magnifying glass.