Caloplaca spp.
The red lichen responsible for the orange hue in the rocks of Tasmania’s coastline is of the genus Caloplaca, a common lichen with worldwide distribution belonging to the family Teloschistaceae. Identification of individual lichen species is difficult, but the species at Bay of Fires is often described as Caloplaca marina. It is also sometimes claimed that the vivid coloration of Caloplaca lichens are responsible for the name of the area, but in fact the name was originally applied to the whole north-eastern coastline by Captain Tobias Furneaux in 1773, after he saw the smoke from the fires of the local Kunnara Kuna tribe.
There are a handful of less common species of red crustose lichen in Tasmania, belonging to the family Hymeneliaceae. Hymenelia lacustris prefers wet silicaceous rocks and is often found in fresh water. Hymenelia gyalectoidea grows on alpine and sub-alpine dolerite rocks, and Tremolecia atrata is found only at higher altitudes.
A more complete discussion of the distribution and identification of Hymeneliaceae in Tasmania can be found in this paper by Gintaras Kantvilas at the Tasmanian Herbarium. Although not specifically about Tasmania, the same author has also published an interesting discussion of the diversity of Caloplaca species on Kangaroo Island.