Reindeer moss, also known as lichen, grows in the Arctic and subarctic regions. This unique organism has a symbiotic relationship with fungi. It's an essential food source for reindeer and caribou during the winter months. However, if you are looking for synonyms for reindeer moss, you may come across several names, including caribou lichen, Arctic moss, or Cladonia rangiferina. These names may vary depending on the region and the species of lichen. Nevertheless, the important thing to remember is that reindeer moss has a crucial role in maintaining the ecological balance in the Arctic and the subarctic regions.