About Ramalina siliquosa (Huds.) A.L.Sm.
Ramalina siliquosa, commonly called sea ivory, is a tufted, branched lichen. It is widely distributed on siliceous rocks and stone walls in coastlands around the British Isles, and occasionally occurs a short distance inland. It grows well above the high-tide mark, but remains highly tolerant of salt spray. Its flattened grey branches bear disc-like spore-producing structures. This lichen is part of the diet of sheep in Shetland and on the coast of North Wales. It also occurs in Iceland, where it holds a vulnerable conservation status.