reindeer moss The common name for the lichenCladonia rangiferina and similar species, which form extensively branched podetia up to about 8 cm tall; in C. rangiferina the apices of the branches are slender and curved, typically all in the same direction. These lichens are found, for example, on peaty ground in mountains and in Arctic and sub-Arctic regions where, together with other lichens, they form a major component of the winter diet of reindeer, known in North America as caribou (Rangifer tarandus).