The Vosges mountains are a reservoir of biodiversity. The flora there is diverse, with varieties from the Arctic Circle to maritime essences. The herbaceous layer is mostly dominated by Calluna, or false heather, and blueberries. The muscinal layer is composed of abundant mosses but is especially rich in soil lichens. Cladonia, a moss-like lichen, is often called reindeer lichens because it is used as food during the winter in the polar regions. These vegetables form a silvery carpet on the rocky summit platforms.